TNT2011 Abstract Book by Phantoms Foundation

On behalf of the International, Local and Technical Committees, we take great pleasure in welcoming you to Tenerife (Canary Islands, Spain) for the 12th “Trends in NanoTechnology” (TNT2011) International Conference. TNT2011 is being held in large part due to the overwhelming success of earlier TNT Nanotechnology Conferences and will be organised in a similar way to the prior events. This high-level scientific meeting series aims to present a broad range of current research in Nanoscience and Nanotechnology worldwide, as well as initiatives such as EU/ICT/FET, MANA, CIC nanoGUNE Consolider, etc. TNT events have demonstrated that they are particularly effective in transmitting information and promoting interaction and new contacts among workers in this field. Furthermore, this event offers visitors and sponsors an ideal opportunity to interact with each other. One of the main objectives of the Trends in Nanotechnology conference is to provide a platform where young researchers can present their latest work and also interact with high-level scientists. For this purpose, the Organising Committee provides every year around 60 travel grants for students. In addition, this year, 9 awards (2400 Euros in total) will be given to young PhD students for their contributions presented at TNT. More than 40 senior scientists are involved in the selection process. Grants and awards are funded by the TNT Organisation in collaboration with several governmental and research institutions. TNT is now one of the premier European conferences devoted to nanoscale science and technology. We are indebted to the following Scientific Institutions, Companies and Government Agencies for their financial support: Phantoms Foundation, Donostia International Physics Center (DIPC), Universidad Autónoma de Madrid, Instituto Español de Comercio Exterior (ICEX) & “españa-technology for life” program, NIMS (Nanomaterials Laboratory) and MANA (International Center for Materials and Nanoarchitectonics), University of Fribourg and frimat, Adolphe Merkle Institute, Institute for Bioengineering of Catalonia (IBEC), FEI Company, CNano GSO, TRAIN2 (SUDOE Action), nanoICT Coordination Action (EU/ICT/FET project), nanoCODE (EU/NMP project) and Viajes El Corte Ingles. We would also like to thank the following companies and Institutions for their participation: Avactec, ICEX, nanoscale Biomagnetics, nanotechweb, Omicron Nanotechnology, Raith, CNano GSO and TRAIN2 (SUDOE Action). In addition, thanks must be directed to the staff of all the organising institutions whose hard work has helped the planning and organisation of this conference.

The Organising Committee

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 ORGANISING COMMITTEE

Jose-Maria Alameda (Universidad de Oviedo, Spain) Masakazu Aono (MANA, NIMS, Japan) Robert Baptist (CEA / DRT / LETI, France) Xavier Cartoixa (Universidad Autónoma de Barcelona, Spain) Antonio Correia (Phantoms Foundation, Spain) Pedro Echenique (Donostia International Physics Center - DICP / UPV, Spain) Jose Maria Gonzalez Calbet (Universidad Complutense de Madrid, Spain) Uzi Landman (Georgia Tech, USA) Jose Maria Pitarke (CIC nanoGUNE Consolider, Spain) Ron Reifenberger (Purdue University, USA) Jose Rivas (INL, Portugal) Catalina Ruiz (Universidad de la Laguna, Spain) Juan Jose Saenz (Universidad Autonoma de Madrid, Spain) Josep Samitier (Institute for Bioengineering of Catalonia - Universitat de Barcelona, Spain) Frank Scheffold (University of Fribourg, Switzerland)

INTERNATIONAL SCIENTIFIC COMMITTEE

Masakazu Aono (MANA / NIMS, Japan) Andreas Berger (CIC nanoGUNE Consolider, Spain) Fernando Briones (IMM / CSIC, Spain) Alexander Bittner (CIC nanoGUNE Consolider, Spain) Remi Carminati (Ecole Centrale Paris, France) Jose-Luis Costa Kramer (IMM / CSIC, Spain) Antonio Garcia Martin (IMM / CSIC, Spain) Pierre Legagneux (Thales, France) Annick Loiseau (ONERA - CNRS, France) Rodolfo Miranda (Universidad Autónoma de Madrid, Spain) Stefan Roche (Catalan Institute of Nanotechnology and CIN2, Spain) Josep Samitier (Institute for Bioengineering of Catalonia - Universitat de Barcelona, Spain)

TECHNICAL COMMITTEE

Carmen Chacón Tomé (Phantoms Foundation, Spain) Viviana Estêvão (Phantoms Foundation, Spain) Maite Fernández Jiménez (Phantoms Foundation, Spain) Luis Froufe (Universidad Autónoma de Madrid, Spain) Paloma Garcia Escorial (Phantoms Foundation, Spain) Pedro Garcia Mochales (Universidad Autónoma de Madrid, Spain) Adriana Gil (Nanotec, Spain) Manuel Marques (Universidad Autónoma de Madrid, Spain) Concepción Narros Hernández (Phantoms Foundation, Spain) Joaquin Gaspar Ramon-Laca Maderal (Phantoms Foundation, Spain) Jose-Luis Roldan (Phantoms Foundation, Spain)

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 POSTER AWARDS Funded by

TNT 2011

Award Gwangju Institute of Science & Technology (GIST)

500 US Dollars

NIMS/MANA

300 Euros

IBEC

300 Euros

PHANTOMS Foundation

Ipod Nano

PHANTOMS Foundation

Ipod Nano

PHANTOMS Foundation

Ipod Nano

Private Donation

David Prize: 300 US Dollars

Private Donation

Keren Prize: 300 US Dollars

TNT2011 Organisation

Free registration to the 2012 Conference

November 21-25, 2011

Tenerife - Spain

in collaboration with

presents

“PASSPORT TO PRIZES” PROGRAM At this new edition of the Trends in Nanotechnology conference we are pleased to organise the TNT2011 “Passport to Prizes” program.

How does the “Passport to Prizes” program work? Each TNT2011 conference attendee will find a passport card inside his TNT2011 conference bag. You will take your card around the exhibit hall on Monday, Tuesday and Wednesday. Take this opportunity to visit the stands that the exhibitors have prepared, and to learn about the companies and their new products. Each exhibiting company has received a stamp with a number. Attendees will be responsible for collecting stamps from the participating exhibitors that are listed on their passport. Once you have completed your passport card with 7 stamps, fill in your personal data and take the card to the ticket tumbler located in the Registration Area. Please, do not forget to complete the passport card with your name and institution before you put it into the box. All completed entries will be eligible for a prize drawing that will be conducted on the evening of Wednesday (23/11/2011) during the Poster Award Ceremony. Do not miss this opportunity to win one of our two Digital Cameras (donated by Phantoms Foundation). And remember that winners need to be present to win. So… see you at the conference dinner and the poster award ceremony!

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 PLATINUM SPONSORS

SPONSORS

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 EXHIBITORS

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 EXHIBITORS

Raith manufactures a variety of electron beam/ion beam lithography systems for research and development applications designed to meet the needs of researchers, designers, and engineers in both university and industry settings. Raith nanolithography products range from stand alone electron beam writing tools to retrofit lithography attachments for SEM/FIB. Furthermore Raith develops ultra-high precision stages and navigation packages for failure analysis applications. Raith GmbH Konrad-Adenauer-Allee 8 - PHOENIX West 44263 Dortmund- Germany Phone: +49 (0)231 / 95004 - 0 Fax: +49 (0)231 / 95004 - 460 E-mail: sales@raith.com Web: www.raith.com

The Spanish Institute for Foreign Trade (ICEX) ("Instituto Español de Comercio Exterior") is the Spanish Government agency serving Spanish companies to promote their exports and facilitate their international expansion, assisted by the network of Spanish Embassy’s Economic and Commercial Offices and, within Spain, by the Regional and Territorial Offices. It is part of the Spanish Ministry of Industry, Tourism and Trade ("Ministerio de Industria, Turismo y Comercio"). España, Technology for life: www.spainbussiness.com Web; www.icex.es

TNT 2011

November 21-25, 2011

Tenerife - Spain

TRAIN2 project aims to establish SUDOE region as a leading environment for research, innovation, and training in the fields of nanosciences and nanotechnology. THROUGH: • SHARING CAPABILITIES network of research infrastructures • BOOSTING KNOWLEDGE collaborative research projects • INVESTING IN PEOPLE training strategy • EXCHANGING GOOD PRACTICES technology transfer & Entrepreneurship Contact details PROJECT COORDINATOR: Prof. Dr. M. Ricardo Ibarra PROJECT ADMINISTRATOR: Dr. Maite Bona Universidad de Zaragoza E-mail: mbg@unizar.es Web site: http://train2.eu

The C'Nano Grand Sud Ouest (C'Nano GSO) is one of the C'Nano competence centres spread throughout France. C'Nano GSO acts to: • • • • • • •

Promote activities on nanoscience and nanotechnology throughout the French South West area; Promote the emergence of unifying themes; Share tools and equipment performance; Build partnerships with national regions or European countries; Develop effective partnerships with industry; Participate to training at any level; Keep inform general public on developments in nanoscience and nanotechnology.

Web site: http://www.cnanogso.org

TNT 2011

November 21-25, 2011

Tenerife - Spain

Nanotechnology has been our everyday business since long before the term ever existed. Founded in 1984 by Norbert Nold, Omicron started business by introducing the SPECTALEED and the legendary Ultra High Vacuum STM 1 as their first and highly successful products. The STM 1, which still delivers state-of-the-art performance even by today's standards in nearly 200 laboratories worldwide, firmly established Omicron's present position as the world market leader in UHV scanning probe microscopy. Today, our products like, for example, the new NanoESCA or the UHV Gemini Column are right at the forefront of research. We are used to redefining the limits of the technically feasible again and again. More than 500 articles demonstrate this to the full. Many of them were published in leading journals such as Nature, Science, Physical Review Letters or Chemical Review Letters. Omicron NanoTechnology GmbH Limburger Str. 75 65232 Taunusstein Germany Tel: 06128/987-0 Fax: 06128/987-185 E-mail: info@omicron.de Web: http://www.omicron.de

With more than 20 years experience, AVACTEC is in a unique position to offer the finest products and technical guidance for customers in Spain and Portugal looking for UHV and high-vacuum components, vacuum deposition equipment or gas abatement systems. AVACTEC is the exclusive distributor in Spain for companies such as: Allectra - Electrical feedthroughs and other vacuum components CS Clean Systems - Dry-bed gas abatement Mantis Deposition - Vacuum deposition systems and coating services UHV Design - UHV motion and heating products We also offer a complete range of deposition consumables such as sputter targets, evaporation materials, crucibles etc. E-mail: info@avactec.es Web: www.avactec.com

TNT 2011

November 21-25, 2011

Tenerife - Spain

Experts on scientific and biomedical instrumentation nB nanoScale Biomagnetics is a technology based company dedicated to the production of scientific and biomedical instruments for induction heating experiments of nanostructured materials, whose main application is on Magnetic Hyperthermia. Formed in 2008 as a Spin Off Company coming from the University of Zaragoza, nB enters the market in 2010 with the DM100 Series: the integral, immediate and reliable solution for Magnetic Hyperthermia laboratory trials. nB nanoScale Biomagnetics is your ideal partner for your needs and initiatives on scientific and biomedical instrumentation. nB nanoScale Biomagnetics is instrumentation for your ideas. E-mail: contact@nbnanoscale.com Web: www.nbnanoscale.com

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT 2011

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAM

TNT 2011

November 21-25, 2011

Tenerife - Spain

TNT2011 - POSTER PRESENTATION DETAILS Poster size: A0 format (width: 841 mm x Height: 1189 mm) (Portrait) Poster Session â&#x20AC;&#x201C; seniors & students: From Monday morning to Tuesday evening.

K: Keynote Lecture (30 min. including discussion time) O: Oral Presentation (15 min. including discussion time) PS: Poster Session

TNT 2011

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 Monday - November 21, 2011 08h00-09h00

REGISTRATION

09h00-09h15

TNT2011 Opening Ceremony - Welcome and Introduction Chairman: Juan Jose Saenz (UAM, Spain) 09h15-09h45 Uzi Landman (Georgia Institute of Technology, USA) K "Small is different: emergent fluid behavior in the nanoscale" p. 63 09h45-10h15 Masakazu Aono (MANA / NIMS, Japan) K "Controlling single-molecule-level chemical reactions at designated positions" p. 1 10h15-10h45 Tsuyoshi Hasegawa (NIMS, Japan) K "Atom/ion movement controlled three-terminal atomic switch, ‘Atom Transistor" p. 47 10h45-11h15 Coffee Break - Poster Session - Instrument Exhibition PS “Graphene” Session – Sponsored by nanoICT CA / Chairman: Ivan Brihuega (UAM, Spain) 11h15-11h45 Stephan Roche (ICN and CIN2, Spain) "Transport Properties in Disordered Graphene : Effects of Atomic Hydrogen and K p. 97 Structural Defects" 11h45-12h15 Pierre Seneor (CNRS/THALES, France) K "Graphene Spintronics" p. 117 12h15-12h45 Francesco Bonaccorso (University of Cambridge, UK) K "Graphene Photonics and Optoelectronics" p. 9 12h45-13h00 Saverio Russo (University of Exeter, United Kingdom) O "Nano-patterning of fluorinated graphene by electron beam irradiation" p. 101 13h00-13h15 Udo Schwalke (TU-Darmstadt, Germany) "In-Situ CCVD Growth of Hexagonal Carbon for CMOS-Compatible O p. 115 Nanoelectronics: From Nanotube Field-Effect Devices to Graphene Transistors" 13h15-15h00 Cocktail Lunch (offered by TNT2011) - Poster Session - Instrument Exhibition “Graphene” Session – Sponsored by nanoICT CA / Chairman: Stephan Roche (ICN & CIN2, Spain) 15h00-15h30 Ivan Brihuega (Universidad Autonoma de Madrid, Spain) K "Point defects in graphene systems" p. 11 15h30-16h00 Johann Coraux (Institut Néel - CNRS, France) K "Epitaxial graphene on metals and hybrid systems " p. 27 16h00-16h30 Chris Ewels (IMN - CNRS, France) K "Distorting graphene through mechanics and edge chemistry" p. 33 16h30-17h00 Coffee Break - Poster Session A - Instrument Exhibition PS “Soft Matter” Session – Sponsored by FRIMAT / Chairman: Frank Scheffold (FRIMAT, Switzerland) 17h00-17h30 Peter Schurtenberger (Lund University, Sweden) K "Thermo-responsive smart materials" p. 113 17h30-18h00 Igor Musevic (University of Ljubljana, Slovenia) "Nematic Colloidal Crystals, Microresonators and 3D Microlasers for Soft K p. 79 Matter Photonics" 18h00-18h30 Erin Koos (Karlsruhe Institute of Technology (KIT), Germany) K "Particle configurations and gelation in capillary suspensions" p. 61 18h30-19h00 Ana Stradner (Fribourg Center for Nanomaterials, Switzerland) K "A nanoscience-based approach to protein condensation diseases" p. 125

TNT 2011

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 Tuesday - November 22, 2011 Chairman: Antonio Garcia Martin (IMM-CSIC, Spain) Thomas Schrefl (Vienna University of Technology, Austria) K "Simulation of nano-scale magnetic systems" Stéphane Mangin (Institut Jean Lamour - CNRS, France) "Low and fast magnetization dynamic driven by spin transfer torque in K p. 67 nanopillar spinvalve with strong perpendicular anisotropty" 10h00-10h30 Uwe Hartmann (Saarland University, Germany) K "Domain-structure-induced giant magneto-impedance" p. 45 10h30-11h00 Andreas Berger (nanoGUNE, Spain) "Generalized Magneto-Optical Ellipsometry (GME) for Magnetic Materials K p. 5 Characterization" 11h00-11h30 Coffee Break - Poster Session - Instrument Exhibition PS “BioInspired” Session – Sponsored by TRAIN2 / Chairman: Jean-Pierre Aimé (Univ. Bordeaux1, France) 11h30-12h00 Friedrich C. Simmel (Technische Universität München, Germany) K "Nucleic-acid based molecular structures, devices and circuits" p. 121 12h00-12h30 Ronen Polsky (Sandia National Laboratories, USA) K "Lithographically-Defined Nano/Micro Structures for Biological Sensing Applications" p. 89 12h30-12h45 Alekber Kasumov (Laboratoire de Physique des Solides, France) O "Proximity induced superconductivity in DNAs" p. 59 12h45-13h00 Samuel Sánchez Ordoñez (Inst. for Integrative Nanosciences, Germany) "Nanobiochemical applications of rolled-up nanomembranes for: From O p. 105 Nanorobotics to Lab-in-a-tube systems" 13h00-13h15 Alpana Nayak (MANA/NIMS, Japan) O "Biological synapse mimicked in an inorganic Cu2S gap-type atomic switch" p. 81 13h15-15h00 Lunch “BioInspired” Session – Sponsored by TRAIN2 & IBEC / Chairman: Ronen Polsky (Sandia, USA) 15h00-15h30 Pascal Colpo (JRC Ispra, Italy) K "Application of plasma technologies to biological interface design" p. 25 15h30-16h00 Lino Reggiani (Universita' degli Studi di Lecce, Italy) K "Microscopic modeling of charge transport in sensing proteins" p. 93 Elena Martinez (IBEC, Spain) 16h00-16h15 "Cell behavior by the controlled immobilization of biotinylated proteins in a gradient O p. 71 fashion: non-linear concentration effects produced by unnoticed ligand nanoclustering" 16h15-16h30 Jean-Jacques Toulme (University of Bordeaux - Inserm U869, France) O "Aptamer-based scaffolds for developments in nanotechnology" 129 16h30-17h00 Coffee Break - Poster Session - Instrument Exhibition PS “BioInspired” Session – Sponsored by TRAIN2 / Chairman: Pascal Colpo (JRC Ispra, Italy) 17h00-17h30 Jean-Louis Mergny (Université Bordeaux Segalen, France) K "Unusual nucleic acid structures: applications to nano- and biotechnologies" p. 73 17h30-18h00 Peter A. Lieberzeit (University of Vienna, Austria) K "Nanostructured materials with biomimetic recognition abilities for chemical sensing p. 65 18h00-18h30 Victoria Birkedal (Aarhus University, Denmark) K "Conformation changes of man-made DNA nanostructures" p. 7 18h30-19h00 Kurt E. Geckeler (Gwangju Institute of Science & Technology (GIST), Korea) K "Nanobiocomposites with Graphene: Design and Perspectives" p. 39 09h00-09h30 p. 111 09h30-10h00

TNT 2011

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 Wednesday - November 23, 2011 Chairman: Johann Coraux (Institut Néel - CNRS, France) Shintaro Sato (AIST, Japan) "Application of graphene to transistors: CVD growth, nanoribbon formation, p. 109 and electrical properties" 09h30-10h00 José A. Martín Gago (ICMM-CSIC, Spain) "Adsorption, cyclo-dehydrogentaion and graphene formation from large p. 69 molecular precursors on catalytic surfaces" 10h00-10h30 Leo Gross (IBM Research, Switzerland) "High-Resolution Molecular Imaging with STM and AFM using Functionalized p. 43 Tips" 10h30-11h00 Thomas Frederiksen (DIPC, Spain) "Atomic-scale engineering of electrodes for single-molecule contacts" p. 35 11h00-11h30 Kohei Uosaki (NIMS/ MANA, Japan) "Interfacial Arrangements with Atomic/Molecular Resolution for Highly p. 131 Efficient Photoelectrochemical Energy Conversion" 11h30-12h00 Coffee Break - Poster Session - Instrument Exhibition “Risks and Regulations” Session – Sponsored by nanoCODE / Chairman: Maite Fernandez (Phantoms Foundation, Spain) 12h00-12h30 Aida Ponce Del Castillo (ETUI, Belgium) p. 12h30-13h00 Yves Sicard (UJF-CEA, France) "Nanosmile website on nanosafety,Training, Education and Public dialogue p. 119 issues" 13h00-14h45 Cocktail Lunch (offered by TNT2011) - Poster Session - Instrument Exhibition Chairman: Thomas Frederiksen (DIPC, Spain) 14h45-15h00 Josef Havel (Masaryk University, Czech Republic) "Time of Flight Mass Spectrometry for analysis of nano- and plasma modified p. 49 materials" 15h00-15h15 Ricardo Riguera (Universidad de Santiago de Compostela, Spain) "Dynamic Helical Polymers: Sensors for the Valence of Metal Cations" p. 95 15h15-15h30 Dae Joon Kang (Sungkyunkwan University, Korea) "Surface Stress-induced Domain Dynamics and Phase Transitions in Epitaxially p. 123 Grown VO2 Nanowires" 15h30-16h45 Parallel Session: “PhD” NanoCode Satellite Workshop 16h45-17h15 Coffee Break - Poster Session - Instrument Exhibition 17h15-19h00 Parallel Session: “Seniors” NanoCode Satellite Workshop 09h00-09h30

21h00 00h00

TNT 2011

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Conference Dinner Poster Award Ceremony

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 - PARALLEL SESSIONS Wednesday - November 23, 2011

15h30-15h45 p. 77 15h45-16h00 p. 91 16h00-16h15 p. 41 16h15-16h30 p. 87 16h30-16h45 p. 103

"PhD" Parallel Session Chairman: Xavier Cartoixa (Universidad Autónoma de Barcelona, Spain) Michael Möller (Universitat de València, Spain) "Polarized recombination of acoustically transported charge carriers in GaAs nanowires" Sebastian Pregl (TU Dresden, Germany) "Parallel Arrays of Silicon-Nanowire Field Effect Transistors for Nanoelectronics and Biosensors" Sonia Gil (Universidad de Castilla La Mancha, Spain) "Catalytic Oxidation of Crude Glycerol using Au Catalyst Based on Carbonaceous Supports" Margo Plaado (University of Tartu, Estonia) "Formation of thick dielectrophoretic carbon nanotube fibers" Aigi Salundi (University of Tartu, Estonia) "New approaches in obtaining nano- and microstructured metal oxide materials with improved properties and functionality"

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SCIENTIFIC PROGRAMME - TNT2011 - PARALLEL SESSIONS Wednesday - November 23, 2011

17h15-17h30 p. 21 17h30-17h45 p. 57 17h45-18h00 p. 127 18h00-18h15 p. 15 18h15-18h30 p. 135 18h30-18h45 p. 53 18h45-19h00 p. 99

TNT 2011

"Seniors" Parallel Session Chairman: Andreas Berger (nanoGUNE, Spain) Andres Castellanos-Gomez (Delft University of Technology, Netherlands) "Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2" Akira Ishii (Tottori University, Japan) "Density functional calculation for various adatom adsorptions on graphene for using graphene as substrate of nanomaterial" Tanel Tätte (University of Tartu, Estonia) "Application of sol-jets in preparation of different shape metal oxide materials" Daniela Cardinale (INRA, France) "Virus scaffolds as Enzyme Nano-Carriers (ENCs)" Arcady Zhukov (UPV/EHU, Spain) "Effect of magnetoelastic anisotropy on domain wall dynamics in amorphous microwires" Yoshihiro Hosokawa (Kyoto University, Japan) "Measurement of tip-sample interaction forces under infrared irradiation toward high-spatial-resolution infrared spectroscopy using FM-AFM (2)" Gabino Rubio-Bollinger (Universidad Autonoma de Madrid, Spain) "Carbon fiber tips for scanning probe microscopes and molecular electronics experiments"

November 21-25, 2011

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Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 - NanoCode Satellite Workshop Wednesday - November 23, 2011

15h30-15h45 15h45-16h00 16h00-16h30 16h30-16h45 16h45-17h15 17h15-17h45 17h45-18h15

nanoCODE Satellite Workshop Chairman: Maite Fernandez (Phantoms Foundation, Spain) Maite Fernandez (Phantoms Foundation, Spain) "nanoCODE project overview” Yves Sicard (UJF-CEA, France)

Fernando Briones (IMM-CSIC, Spain) "Research Ethics and nanoScience" Discussion Coffee Break - Poster Session A - Instrument Exhibition Francisco Balas (INA / CIBER-BBN, Spain) "Engineering Aspects of Nanosafety" Philipp Rosenkranz (INIA, Spain) “Spanish contribution to the Sponsorship Program for the Safety Testing of Manufactured Nanomaterials”

18h15-18h45

Ruth Jiménez Saavedra (ISTAS-CCOO, Spain)

18h45-19h15

Discussion & Conclusions

TNT 2011

November 21-25, 2011

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Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 Thursday - November 24, 2011

13h30-13h45 p. 55 13h45-14h00 p. 3 14h00-14h15 p. 137 14h15-14h30 p. 133 14h30-14h45 p. 19 14h45-15h00

15h00-15h15 p. 15h15-15h45 p. 15h45-16h15 p. 85 16h15-16h45 p. 31 16h45-17h00 p. 17h00-17h30 17h30-18h00 p. 18h00-18h30 p. 18h30-19h00 p. 19h00-19h15

TNT 2011

Chairman: Massimo Macucci (University of Pisa, Italy) Georg Huhs (Barcelona Supercomputing Center, Spain) "Sakurai-Sugiura algorithm based eigenvalue solver for Siesta" Alexander Bagaturyants (Russian Academy of Science, Russia) "Atomistic Multiscale Simulation of Nanostructured Materials for Photonic Applications" Michal Zielinski (Uniwerstytet Mikolaja Kopernika, Poland) "Atomistic modeling of multimillion atom nanosystems" Wolfgang Wenzel (Karlsruhe Institute of Technology, Germany) "Multiscale modelling of nanoscale materials and electronic transport" Xavier Cartoixa Soler (Universitat Autonoma de Barcelona, Spain) "Doping and sensing in silicon nanowires" Pause Satellite Workshop MULT-EU-SIM Chairman: Thierry Deutsch (CEA, France) Thierry Deutsch (CEA / L_Sim, France) "MULT-EU-SIM project overview" Massimo Macucci (Universita di Pisa, Italy) "Analysis of the perspectives of multiscale simulation of devices and circuits" Pablo Ordejon (CIN2,Spain) "Beating the size limits of first-principles calculations in nanoscale systems" Ricardo Diez Muino (CFM/CSIC-UPV/EHU, Spain) "A time-dependent view of electronic excitations in the nanoscale" Sebastian Radke (TU Dresden, Germany) "Charge transport in organic semiconductors: Ab initio charge carrier propagation schemes" Coffee Break Bernard Querleux (l'Oreal, France) "Numerical Modelling at L'Oreal R&I: Present and future" Maurizio Fermeglia (Trieste University, Italy) "Nano tools for macro problems: multiscale molecular modeling of nanostrucured systems" Geoffroy Hautier (Universite Catholique Louvain, Belgium) "High-throughput ab initio computations for materials design"

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Concluding Remarks

November 21-25, 2011

Tenerife - Spain

SCIENTIFIC PROGRAMME - TNT2011 Friday - November 25, 2011

09h00-09h15 p. 13 09h15-09h30 p. 107 09h30-09h45 p. 37 09h45-10h15 p. 17 10h15-10h45 p. 51 10h45-11h15 11h15-11h45 p. 83 11h45-12h00 p. 75 12h00-12h15 p. 29 12h15-12h45 p. 23 12h45-13h00

TNT 2011

Chairman: Dimitris Niarchos (IMS - NCSR Demokritos, Greece) Nestor Capuj (Universidad de La Laguna, Spain) "Combination of optical microtransmission and microphotoluminescence techniques for local characterization of rare earth doped glass microspheres" Jose A. Sánchez-Gil (Instituto de Estructura de la Materia (CSIC), Spain) "Higher-order resonances in single-arm nanoantennas: Evidence of Fano-like interference" Antonio Garcia-Martin (IMM-CNM-CSIC, Spain) "Hybrid photonic-plasmonic crystals based on self-assembled structures" Rémi Carminati (ESPCI, France) "Probing confined photons in nanoscale disordered media from inside" Rainer Hillenbrand (nanoGUNE, Spain) "Infrared and Terahertz Nanoscopy" Coffee Break Chairman: Rémi Carminati (ESPCI, France) Dimitris Niarchos (IMS - NCSR Demokritos, Greece) "Graded exchange spring media based on FePt" Puneet Mishra (MANA/NIMS, Japan) "Enhanced spin contrast detection by spin-polarized scanning tunneling microscopy of antiferromagnetic Mn/Fe(100) films" Fernando Delgado Acosta (INL International Iberian Nanotechnology Laboratory, Portugal) "Probing the nuclear spin of a single donor in Silicon nanotransistors" Alfonso Cebollada (IMM-CSIC, Spain) "Optimizing light harvesting for high magneto-optical performance in metaldielectric magnetoplasmonic nanodiscs" CLOSING REMARKS & TNT2012 ANNOUNCEMENT

November 21-25, 2011

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Tenerife - Spain

TNT 2011

November 21-25, 2011

Tenerife - Spain

INDEX - KEYNOTE CONTRIBUTIONS Masakazu Aono (MANA / NIMS, Japan) "Controlling single-molecule-level chemical reactions at designated positions" Andreas Berger (nanoGUNE, Spain) "Generalized Magneto-Optical Ellipsometry (GME) for Magnetic Materials Characterization" Victoria Birkedal (Aarhus University, Denmark) "Conformational changes of man-made DNA nanostructures" Francesco Bonaccorso (University of Cambridge, UK) "Graphene Photonics and Optoelectronics" Ivan Brihuega (Universidad Autonoma de Madrid, Spain) "Point defects in graphene systems" Rémi Carminati (ESPCI, France) "Probing confined photons in nanoscale disordered media from inside" Alfonso Cebollada (IMM-CSIC, Spain) "Optimizing light harvesting for high magneto-optical performance in metal-dielectric magnetoplasmonic nanodiscs" Pascal Colpo (JRC Ispra, Italy) "Application of plasma technologies to biological interface design" Johann Coraux (Institut Néel - CNRS, France) "Epitaxial graphene on metals and hybrid systems" Ricardo Diez Muino (CFM/CSIC-UPV/EHU, Spain) "A time-dependent view of electronic excitations in the nanoscale" Chris Ewels (IMN - CNRS, France) "Distorting graphene through mechanics and edge chemistry" Thomas Frederiksen (DIPC, Spain) "Atomic-scale engineering of electrodes for single-molecule contacts" Kurt E. Geckeler (Gwangju Institute of Science & Technology (GIST), Korea) "Nanobiocomposites with Graphene: Design and Perspectives" Leo Gross (IBM Research, Switzerland) "High-Resolution Molecular Imaging with STM and AFM using Functionalized Tips" Uwe Hartmann (Saarland University, Germany) "Domain-structure-induced giant magneto-impedance" Tsuyoshi Hasegawa (NIMS, Japan) "Atom/ion movement controlled three-terminal atomic switch, 'Atom Transistor'" Rainer Hillenbrand (nanoGUNE, Spain) "Infrared and Terahertz Nanoscopy" Erin Koos (Karlsruhe Institute of Technology (KIT), Germany) "Particle configurations and gelation in capillary suspensions" Uzi Landman (Georgia Tech, USA) "Small is Different: Emergent Fluid Behavior in the Nanoscale" Peter A. Lieberzeit (University of Vienna, Austria) "Nanostructured materials with biomimetic recognition abilities for chemical sensing" Stéphane Mangin (Institut Jean Lamour - CNRS, France) "Low and fast magnetization dynamic driven by spin transfer torque in nanopillar spinvalve with strong perpendicular anisotropty"

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November 21-25, 2011

p. 1 p. 5 p. 7 p. 9 p. 11 p. 17 p. 23 p. 25 p. 27 p. 31 p. 33 p. 35 p. 39 p. 43 p. 45 p. 47 p. 51 p. 61 p. 63 p. 65 p. 67

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José A. Martin Gago (ICMM-CSIC, Spain) "Adsorption, cyclo-dehydrogentaion and graphene formation from large molecular precursors on catalytic surfaces" Jean-Louis Mergny (Université Bordeaux Segalen, France) "Unusual nucleic acid structures: applications to nano- and biotechnologies" Igor Musevic (University of Ljubljana, Slovenia) "Nematic Colloidal Crystals, Microresonators and 3D Microlasers for Soft Matter Photonics" Dimitris Niarchos (IMS - NCSR Demokritos, Greece) "Graded exchange spring media based on FePt" Pablo Ordejon (CIN2 / CSIC-ICN, Spain) "Beating the size limits of first-principles calculations in nanoscale systems" Ronen Polsky (Sandia National Laboratories, USA) "Lithographically-Defined Nano/Micro Structures for Biological Sensing Applications" Aida Ponce Del Castillo (ETUI, Belgium) Lino Reggiani (Universita' degli Studi di Lecce, Italy) "Microscopic modeling of charge transport in sensing proteins" Stephan Roche (Catalan Institute of Nanotechnology and CIN2, Spain) "Transport Properties in Disordered Graphene : Effects of Atomic Hydrogen and Structural Defects" Shintaro Sato (AIST, Japan) "Application of graphene to transistors: CVD growth, nanoribbon formation, and electrical properties" Thomas Schrefl (Vienna University of Technology, Austria) "Simulation of nano-scale magnetic systems" Peter Schurtenberger (Lund University, Sweden) "Thermo-responsive smart materials" Pierre Seneor (CNRS/THALES, France) "Graphene Spintronics" Yves Sicard (UJF-CEA, France) "Nanosmile website on nanosafety,Training, Education and Public dialogue issues" Friedrich C. Simmel (Technische Universität München, Germany) "Nucleic-acid based molecular structures, devices and circuits" Ana Stradner (Fribourg Center for Nanomaterials, Switzerland) "A nanoscience-based approach to protein condensation diseases" Kohei Uosaki (NIMS/ MANA, Japan) "Interfacial Arrangements with Atomic/Molecular Resolution for Highly Efficient Photoelectrochemical Energy Conversion"

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INDEX – ORAL CONTRIBUTIONS (SENIOR PLENARY SESSION) Alexander Bagaturyants (Russian Academy of Science, Russia) "Atomistic Multiscale Simulation of Nanostructured Materials for Photonic Applications" Nestor Capuj (Universidad de La Laguna, Spain) "Combination of optical microtransmission and microphotoluminescence techniques for local characterization of rare earth doped glass microspheres" Xavier Cartoixa Soler (Universitat Autonoma de Barcelona, Spain) "Doping and sensing in silicon nanowires" Fernando Delgado Acosta (INL International Iberian Nanotechnology Laboratory, Portugal) "Probing the nuclear spin of a single donor in Silicon nanotransistors" Antonio Garcia-Martin (IMM-CNM-CSIC, Spain) "Hybrid photonic-plasmonic crystals based on self-assembled structures" Josef Havel (Masaryk University, Czech Republic) "Time of Flight Mass Spectrometry for analysis of nano- and plasma modified materials" Georg Huhs (Barcelona Supercomputing Center, Spain) "Sakurai-Sugiura algorithm based eigenvalue solver for Siesta" Alekber Kasumov (Laboratoire de Physique des Solides, France) "Proximity induced superconductivity in DNAs" Elena Martinez (IBEC, Spain) "Cell behavior by the controlled immobilization of biotinylated proteins in a gradient fashion: non-linear concentration effects produced by unnoticed ligand nanoclustering" Puneet Mishra (MANA/NIMS, Japan) "Enhanced spin contrast detection by spin-polarized scanning tunneling microscopy of antiferromagnetic Mn/Fe(100) films" Alpana Nayak (MANA/NIMS, Japan) "Biological synapse mimicked in an inorganic Cu2S gap-type atomic switch" Ricardo Riguera (Universidad de Santiago de Compostela, Spain) "Dynamic Helical Polymers: Sensors for the Valence of Metal Cations" Saverio Russo (University of Exeter, United Kingdom) "Nano-patterning of fluorinated graphene by electron beam irradiation" Samuel Sánchez Ordoñez (Institute for Integrative Nanosciences, Germany) "Nanobiochemical applications of rolled-up nanomembranes for: From Nanorobotics to Labin-a-tube systems" Jose A. Sánchez-Gil (Instituto de Estructura de la Materia (CSIC), Spain) "Higher-order resonances in single-arm nanoantennas: Evidence of Fano-like interference" Udo Schwalke (TU-Darmstadt, Germany) "In-Situ CCVD Growth of Hexagonal Carbon for CMOS-Compatible Nanoelectronics: From Nanotube Field-Effect Devices to Graphene Transistors" Junginn Sohn (Samsung Advanced Institute of Technology, Korea) "Surface Stress-induced Domain Dynamics and Phase Transitions in Epitaxially Grown VO2 Nanowires" Jean-Jacques Toulme (University of Bordeaux - Inserm U869, France) "Aptamer-based scaffolds for developments in nanotechnology"

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Wolfgang Wenzel (Karlsruhe Institute of Technology, Germany) "Multiscale modelling of nanoscale materials and electronic transport" Michal Zielinski (Uniwerstytet Mikolaja Kopernika, Poland) "Atomistic modeling of multimillion atom nanosystems."

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INDEX – ORAL CONTRIBUTIONS (SENIOR PARALLEL SESSIONS) Daniela Cardinale (INRA, France) "Virus scaffolds as Enzyme Nano-Carriers (ENCs)" Andres Castellanos-Gomez (Delft University of Technology, Netherlands) "Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2" Yoshihiro Hosokawa (Kyoto University, Japan) "Measurement of tip-sample interaction forces under infrared irradiation toward highspatial-resolution infrared spectroscopy using FM-AFM (2)" Akira Ishii (Tottori University, Japan) "Density functional calculation for various adatom adsorptions on graphene for using graphene as substrate of nanomaterial" Gabino Rubio-Bollinger (Universidad Autonoma de Madrid, Spain) "Carbon fiber tips for scanning probe microscopes and molecular electronics experiments" Tanel Tätte (University of Tartu, Estonia) "Application of sol-jets in preparation of different shape metal oxide materials" Arcady Zhukov (UPV/EHU, Spain) "Effect of magnetoelastic anisotropy on domain wall dynamics in amorphous microwires"

p. 15 p. 21

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INDEX – ORAL CONTRIBUTIONS (PHD PARALLEL SESSION) Sonia Gil (Universidad de Castilla La Mancha, Spain) "Catalytic Oxidation of Crude Glycerol using Au Catalyst Based on Carbonaceous Supports" Michael Möller (Universitat de València, Spain) "Polarized recombination of acoustically transported charge carriers in GaAs nanowires" Margo Plaado (University of Tartu, Estonia) "Formation of thick dielectrophoretic carbon nanotube fibers" Sebastian Pregl (TU Dresden, Germany) "Parallel Arrays of Silicon-Nanowire Field Effect Transistors for Nanoelectronics and Biosensors" Aigi Salundi (University of Tartu, Estonia) "New approaches in obtaining nano- and microstructured metal oxide materials with improved properties and functionality"

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p. 41 p. 77 p. 87 p. 91

p. 103

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ALPHABETICAL ORDER K: Keynote / O: Oral / PS: Parallel Session / SW: Satellite Workshop Masakazu Aono (MANA / NIMS, Japan) "Controlling single-molecule-level chemical reactions at designated positions" Francisco Balas (INA / CIBER-BBN, Spain) "Engineering Aspects of Nanosafety" Alexander Bagaturyants (Russian Academy of Science, Russia) "Atomistic Multiscale Simulation of Nanostructured Materials for Photonic Applications" Andreas Berger (nanoGUNE, Spain) "Generalized Magneto-Optical Ellipsometry (GME) for Magnetic Materials Characterization" Victoria Birkedal (Aarhus University, Denmark) "Conformational changes of man-made DNA nanostructures" Francesco Bonaccorso (University of Cambridge, UK) "Graphene Photonics and Optoelectronics" Ivan Brihuega (Universidad Autonoma de Madrid, Spain) "Point defects in graphene systems" Fernando Briones (IMM-CSIC, Spain) Nestor Capuj (Universidad de La Laguna, Spain) "Combination of optical microtransmission and microphotoluminescence techniques for local characterization of rare earth doped glass microspheres" Daniela Cardinale (INRA, France) "Virus scaffolds as Enzyme Nano-Carriers (ENCs)" Remi Carminati (ESPCI, France) "Probing confined photons in nanoscale disordered media from inside" Xavier Cartoixa Soler (Universitat Autonoma de Barcelona, Spain) "Doping and sensing in silicon nanowires" Andres Castellanos-Gomez (Delft University of Technology, Netherlands) "Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2" Alfonso Cebollada (IMM-CSIC, Spain) "Optimizing light harvesting for high magneto-optical performance in metal-dielectric magnetoplasmonic nanodiscs" Pascal Colpo (JRC Ispra, Italy) "Application of plasma technologies to biological interface design" Johann Coraux (Institut NĂŠel - CNRS, France) "Epitaxial graphene on metals and hybrid systems" Fernando Delgado Acosta (INL International Iberian Nanotechnology Laboratory, Portugal) "Probing the nuclear spin of a single donor in Silicon nanotransistors" Thierry Deutsch (CEA / L_Sim, France) "MULT-EU-SIM project overview" Ricardo Diez Muino (CFM/CSIC-UPV/EHU, Spain) "A time-dependent view of electronic excitations in the nanoscale"

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Chris Ewels (IMN - CNRS, France) "Distorting graphene through mechanics and edge chemistry" Maurizio Fermeglia (Trieste University, Italy) "Nano tools for macro problems: multiscale molecular modeling of nanostrucured systems" Maite Fernandez (Phantoms Foundation, Spain) "nanoCODE project overviewâ&#x20AC;? Thomas Frederiksen (DIPC, Spain) "Atomic-scale engineering of electrodes for single-molecule contacts" Antonio Garcia-Martin (IMM-CNM-CSIC, Spain) "Hybrid photonic-plasmonic crystals based on self-assembled structures" Kurt E. Geckeler (Gwangju Institute of Science & Technology (GIST), Korea) "Nanobiocomposites with Graphene: Design and Perspectives" Sonia Gil (Universidad de Castilla La Mancha, Spain) "Catalytic Oxidation of Crude Glycerol using Au Catalyst Based on Carbonaceous Supports" Leo Gross (IBM Research, Switzerland) "The importance of tip functionalization in imaging molecules with STM and AFM" Uwe Hartmann (Saarland University, Germany) "Domain-structure-induced giant magneto-impedance" Tsuyoshi Hasegawa (NIMS, Japan) "Atom/ion movement controlled three-terminal atomic switch, 'Atom Transistor'" Geoffroy Hautier (Universite Catholique Louvain, Belgium) "High-throughput ab initio computations for materials design" Josef Havel (Masaryk University, Czech Republic) "Time of Flight Mass Spectrometry for analysis of nano- and plasma modified materials" Rainer Hillenbrand (nanoGUNE, Spain) "Infrared and Terahertz Nanoscopy" Yoshihiro Hosokawa (Kyoto University, Japan) "Measurement of tip-sample interaction forces under infrared irradiation toward high-spatial-resolution infrared spectroscopy using FM-AFM (2)" Georg Huhs (Barcelona Supercomputing Center, Spain) "Sakurai-Sugiura algorithm based eigenvalue solver for Siesta" Akira Ishii (Tottori University, Japan) "Density functional calculation for various adatom adsorptions on graphene for using graphene as substrate of nanomaterial" Ruth JimĂŠnez Saavedra (ISTAS-CCOO, Spain) Alekber Kasumov (Laboratoire de Physique des Solides, France) "Proximity induced superconductivity in DNAs" Erin Koos (Karlsruhe Institute of Technology (KIT), Germany) "Particle configurations and gelation in capillary suspensions" Uzi Landman (Georgia Tech, USA) "Small is Different: Emergent Fluid Behavior in the Nanoscale" Peter A. Lieberzeit (University of Vienna, Austria) "Nanostructured materials with biomimetic recognition abilities for chemical sensing" Massimo Macucci (Universita di Pisa, Italy) "Analysis of the perspectives of multiscale simulation of devices and circuits"

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Stéphane Mangin (Institut Jean Lamour - CNRS, France) "Low and fast magnetization dynamic driven by spin transfer torque in nanopillar spinvalve with strong perpendicular anisotropty" José A. Martin Gago (ICMM-CSIC, Spain) "Adsorption, cyclo-dehydrogentaion and graphene formation from large molecular precursors on catalytic surfaces" Elena Martinez (IBEC, Spain) "Cell behavior by the controlled immobilization of biotinylated proteins in a gradient fashion: non-linear concentration effects produced by unnoticed ligand nanoclustering" Jean-Louis Mergny (Université Bordeaux Segalen, France) "Unusual nucleic acid structures: applications to nano- and biotechnologies" Puneet Mishra (MANA/NIMS, Japan) "Enhanced spin contrast detection by spin-polarized scanning tunneling microscopy of antiferromagnetic Mn/Fe(100) films" Michael Möller (Universitat de València, Spain) "Polarized recombination of acoustically transported charge carriers in GaAs nanowires" Igor Musevic (University of Ljubljana, Slovenia) "Nematic Colloidal Crystals, Microresonators and 3D Microlasers for Soft Matter Photonics" Alpana Nayak (MANA/NIMS, Japan) "Biological synapse mimicked in an inorganic Cu2S gap-type atomic switch" Dimitris Niarchos (IMS - NCSR Demokritos, Greece) "Graded exchange spring media based on FePt" Pablo Ordejon (CIN2 / CSIC-ICN, Spain) "Beating the size limits of first-principles calculations in nanoscale systems" Margo Plaado (University of Tartu, Estonia) "Formation of thick dielectrophoretic carbon nanotube fibers" Ronen Polsky (Sandia National Laboratories, USA) "Lithographically-Defined Nano/Micro Structures for Biological Sensing Applications" Aida Ponce Del Castillo (ETUI, Belgium) Sebastian Pregl (TU Dresden, Germany) "Parallel Arrays of Silicon-Nanowire Field Effect Transistors for Nanoelectronics and Biosensors" Bernard Querleux (l'Oreal, France) "Numerical Modelling at L'Oreal R&I: Present and future" Sebastian Radke (TU Dresden, Germany) "Charge transport in organic semiconductors: Ab initio charge carrier propagation schemes" Lino Reggiani (Universita' degli Studi di Lecce, Italy) "Microscopic modeling of charge transport in sensing proteins" Ricardo Riguera (Universidad de Santiago de Compostela, Spain) "Dynamic Helical Polymers: Sensors for the Valence of Metal Cations" Stephan Roche (Catalan Institute of Nanotechnology and CIN2, Spain) "Transport Properties in Disordered Graphene : Effects of Atomic Hydrogen and Structural Defects"

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Tenerife - Spain

Philipp Rosenkranz (INIA, Spain) “Spanish contribution to the Sponsorship Program for the Safety Testing of Manufactured Nanomaterials” Gabino Rubio-Bollinger (Universidad Autónoma de Madrid, Spain) "Carbon fiber tips for scanning probe microscopes and molecular electronics experiments" Saverio Russo (University of Exeter, United Kingdom) "Nano-patterning of fluorinated graphene by electron beam irradiation" Aigi Salundi (University of Tartu, Estonia) "New approaches in obtaining nano- and microstructured metal oxide materials with improved properties and functionality" Samuel Sánchez Ordoñez (Institute for Integrative Nanosciences, Germany) "Nanobiochemical applications of rolled-up nanomembranes for: From Nanorobotics to Lab-in-a-tube systems" Jose A. Sánchez-Gil (Instituto de Estructura de la Materia (CSIC), Spain) "Higher-order resonances in single-arm nanoantennas: Evidence of Fano-like interference" Shintaro Sato (AIST, Japan) "Application of graphene to transistors: CVD growth, nanoribbon formation, and electrical properties" Thomas Schrefl (Vienna University of Technology, Austria) "Simulation of nano-scale magnetic systems" Peter Schurtenberger (Lund University, Sweden) "Thermo-responsive smart materials" Udo Schwalke (TU-Darmstadt, Germany) "In-Situ CCVD Growth of Hexagonal Carbon for CMOS-Compatible Nanoelectronics: From Nanotube Field-Effect Devices to Graphene Transistors" Pierre Seneor (CNRS/THALES, France) "Graphene Spintronics" Yves Sicard (UJF-CEA, France) "Nanosmile website on nanosafety,Training, Education and Public dialogue issues" Friedrich C. Simmel (Technische Universität München, Germany) "Nucleic-acid based molecular structures, devices and circuits" Junginn Sohn (Samsung Advanced Institute of Technology, Korea) "Surface Stress-induced Domain Dynamics and Phase Transitions in Epitaxially Grown VO2 Nanowires" Ana Stradner (Fribourg Center for Nanomaterials, Switzerland) "A nanoscience-based approach to protein condensation diseases" Tanel Tätte (University of Tartu, Estonia) "Application of sol-jets in preparation of different shape metal oxide materials" Jean-Jacques Toulme (University of Bordeaux - Inserm U869, France) "Aptamer-based scaffolds for developments in nanotechnology" Kohei Uosaki (NIMS/ MANA, Japan) "Interfacial Arrangements with Atomic/Molecular Resolution for Highly Efficient Photoelectrochemical Energy Conversion" Wolfgang Wenzel (Karlsruhe Institute of Technology, Germany) "Multiscale modelling of nanoscale materials and electronic transport"

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Arcady Zhukov (UPV/EHU, Spain) "Effect of magnetoelastic anisotropy on domain wall dynamics in amorphous microwires" Michal Zielinski (Uniwerstytet Mikolaja Kopernika, Poland) "Atomistic modeling of multimillion atom nanosystems."

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ABSTRACTS

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Tenerife - Spain

Controlling single-molecule-level chemical reactions at designated positions

1 M. Aono, Y. Okawa, S.-K. Mandal, T. Nakayana, and M. Nakaya International Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS) Tsukuba, Ibaraki, 305-0044 Japan For several years, we have been studying how to control single-molecule-level chemical reactions at designated positions. The studies have been mainly made for the following two kinds of chemical reactions: 1) Wiring a single functional molecule at a given position with two electrically conductive linear polymer molecules[1-7] and 2) reversibly controlling the creation and annihilation of chemical bonding between two or three C60 molecules at a designated position in a thin C60 molecular film[810]. Recently, we have obtained remarkable progress in both 1) [7] and 2) [10]. Namely, it has been revealed that 1) we can ensure firm covalent bonding between a targeted functional molecule and wired conductive polymer molecules[7] and 2) the formation of the covalently bonded dimer and trimer of C60 molecules can be controlled at will[10]. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

Y. Okawa and M. Aono, Nature 409 (2001) 683. Y. Okawa and M. Aono, J. Chem. Phys. 115 (2001) 2317. Y. Okawa and M. Aono, Surf. Sci. 514 (2002) 41. D. Takajo et al, Langmuir 23 (2007) 5247. Y. Okawa et al., Soft Matter 4 (2008) 1041. S. Mandal et al., ACS Nano 5 (2011) 2779. Y. Okawa et al., J. Am. Chem. Soc. 133 (2011) 8227. M. Nakaya et al., Adv. Mater. 22 (2010) 1622. M. Nakaya et al., J. Nanosci. Nanotechnol. 11 (2011) 2829. M. Nakaya et al., ACS Nano, 5 (2011) 7830.

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November 21-25, 2011

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Atomistic Multiscale Simulation of Nanostructured Materials for Photonic Applications

3 Alexander Bagaturyants, Michael Alfimov Photochemistry Center, Russian Academy of Sciences, ul. Novatorov 7a, build. 1, Moscow 119421 Russia sasha@photonics.ru Nanotechnology is a new, just incipient field of science and engineering, in which substances are controlled at an atomic or molecular level. Because new substances with a prescribed atomic and molecular structure are created in nanotechnologies by means of controlled manipulation with atoms and molecules, the use of multiscale atomistic simulation methods is of fundamental necessity. Hierarchically constructed nanostructured materials, in which the structure of a lower level of scale is built into the structure of a higher level of scale, attract particular interest. The development of nanostructured materials for optical chemical gas sensors is an example of this application. The functionality of such a material is provided by a photoactive molecule (indicator molecule, IM) such that it strongly changes its optical response (mostly, luminescence) upon interaction with a target molecule (detected or analyte molecule, AM). IM represents the lowest level of the hierarchy and is built into a local structure forming a receptor center (RC), which in its turn is built into a nanoparticle (NP). An NP may bear many RCs. Finally, nanoparticles are assembled into a layer or a multilayered structure (nanoparticle assembly, NPA), which may have regular ordering, forming a photonic lattice. The goal of simulation in this case is to predict the optical properties of the entire structure (sensory material) and its response to various AMs. Direct calculations in real time and space scales are impossible with the currently available computational resources. Instead, a multiscale approach is used, in which simulations and calculations at each level of scale are performed using methods and approximations appropriate for the corresponding scale, while the results of modeling the structure and properties of a material at a lower level are transferred as input data to the next, higher level of scale. Modeling materials for the sensing layer of optical chemosensors is considered as an example of the general strategy of multiscale atomistic modeling of hierarchically constructed nanostructured materials for organic nanophotonics. The main steps of such modeling are considered: modeling at the molecular level, modeling at the supramolecular level, and modeling at the level of nanoparticles. Problems arising at each step of modeling are analyzed, and current approaches to their solution are discussed. In our case of hierarchically constructed materials for optical chemosensors, the use of atomistic simulation methods is restricted to the first three levels: IM, RC, and NP. The description of the assembling (self-assembling) of NPs into the final NPA and the prediction of its optical properties and response require the use of continual or phenomenological approaches and is beyond the scope of this paper. Hence, the following levels and the corresponding problems will be considered: â&#x2C6;&#x2019;

â&#x2C6;&#x2019;

molecular level: methods and possibilities, molecular structure, absorption spectra, emission spectra, line shapes, radiative and nonradiative transition probabilities, Stokes shifts, and special cases of large Stokes shifts in organic molecules arising in so-called twisted internal charge transfer (TICT) states; supramolecular level: molecular complexes and complex-formation effects on absorption and emission spectra, the problem of correctly describing intermolecular interactions and the structure of supramolecular systems, corresponding methods and possibilities, interaction

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4 − − −

−

potentials and their construction, reactive potentials, molecular mechanics, quantum and classical molecular dynamics, Monte Carlo methods; nanoparticle level: formation and structure of nanoparticles, coarse-grained potentials and coarse-grained molecular dynamics, kinetic Monte Carlo techniques. The possibilities of modern atomistic simulation methods are considered using specific examples: quantum-chemical or quantum-mechanical simulation methods as applied to relatively small atomic and molecular systems; without these methods, optical, electronic, mechanical, vibrational, chemical and other functional properties of a material cannot be predicted; simulation methods based on the use of classical force fields approximately describing the main features of quantum interactions among atoms in molecules and among molecules themselves (molecular mechanics and modern computational methods of statistical physics, such as molecular dynamics and Monte Carlo methods); in the framework of classical force fields, one can describe the structure, thermodynamics, and dynamics of systems containing about 1000 and much more atoms. Methods taking into account solvation (polarization) effects using both continual and molecular models, which can be used to describe the structure of an AM chemisorbed on a NP.

Special attention is given to the problem of adequately describing intermolecular interactions, the problem of describing functional properties of main molecular or cluster components of a supramolecular system, the problem of conjugating different scales, and the problem of consistently describing the system, in particular, the problem of constructing classical potentials based on the results of quantum calculations, and the problem of describing the formation and growth of supramolecular systems. References [1]

[2]

[3] [4] [5] [6] [7] [8] [9] [10]

A.A. Bagatur'yants, A.Kh. Minushev, K.P. Novoselov, A.A. Safonov, S.Ya. Umanskii, A.S. Vladimirov, A. Korkin, In Predictive Simulation of Semiconductor Processing Status and Challenges, Springer Series in Materials Science, Vol. 72, Dabrowski, J. and Weber, E.R. (Eds.), Springer Verlag, 2004, 295. A.A. Bagatur'yants, M.A. Deminskii, A.A. Knizhnik, B.V. Potapkin, S.Ya. Umanskii, in Thin Films and Nanostructures: Physico–Chemical Phenomena in Thin Films and at Solid Surfaces, L. I. Trakhtenberg, S. H. Lin, O. J. Ilegbusi, eds., Elsevier (2007) 468. A.A. Bagatur’yants, I.M. Iskandarova, A.A. Knizhnik, V.S. Mironov, B.V. Potapkin, A.M. Srivastava, T.J. Sommerer, Phys. Rev. B 78 (2008) 165125. A.N. Vasil’ev, I.M. Iskandarova, A.V. Scherbinin, I.A. Markov, A.A. Bagatur’yants, B.V. Potapkin, A.M. Srivastava, J.S. Vartuli, S.J. Duclos, J. Luminesc. 129 (2009), 1555. K.G. Vladimirova, A.Ya. Freidzon, O.V. Kotova, A.A. Vaschenko, L.S. Lepnev, A.A. Bagatur'yants, A.G. Vitukhnovskiy, N.F. Stepanov, M.V. Alfimov, Inorg. Chem., (2009) 48 (23) 11123. A.Ya. Freidzon, A.A. Bagatur’yants, E.N. Ushakov, S.P. Gromov, M.V. Alfimov, Int. J. Quant. Chem. 111, (2011) 2649. A.A. Safonov, E.A. Rykova, A.A. Bagaturyants, V.A. Sazhnikov, M.V. Alfimov, J. Mol. Mod. 17 (2011) 1855. V. Chashchikhin, E. Rykova, A. Bagaturyants, Phys. Chem. Chem. Phys. 13 (2011) 1440. M.V. Basilevsky, E.A. Nikitina, F.V. Grigoriev, A.A. Bagaturyants, M.V. Alfimov, Struct. Chem. 22 (2011) 427. A.Ya. Freidzon, A.V. Scherbinin, A.A. Bagaturyants, M.V. Alfimov, J. Phys. Chem. A, 115 (2011) 4565.

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Generalized Magneto-Optical Ellipsometry (GME) for Magnetic Materials Characterization A. Berger CIC nanoGUNE Conslider, E-20018, Donostia-San Sebastiรกn, Spain a.berger@nanogune.eu For the past several decades, ellipsometry has proven itself as an advanced measurement and characterization technique for optical materials properties as well as a crucial metrology tool for multilayer and film growth. Its applications are widespread, reaching from basic research to industrial utilization, furthermore initiating the growth of an ellipsometer instrumentation industry. Besides numerous other advantages, ellipsometry is non-destructive, fast, compatible with many environmental conditions and can be implemented even through very simple experimental configurations. A more recently developed implementation and extension of this technique, named Generalized Magneto-Optical Ellipsometry (GME), has emerged during the last decade as a methodology to characterize magnetic materials with a high degree of precision, by means of utilizing the magnetooptical Kerr effect [1-2]. Compared to other magneto-optical characterization methods based on the same effect [3-4], GME has two key advantages: it can measure both the optical and magneto-optical constants simultaneously and with a high degree of precision, and it allows full vector magnetometry, all with only one experimental set-up and measurement configuration. The GME method, which is based on measurements of the light reflection change upon applying a magnetic field cycle, know as hysteresis loop, has been successfully utilized in the study of diverse magnetization reversal processes [5], the investigation of magneto-optical coupling in ferromagnetic films [6], and for the purpose of identifying spin-polarized electronic states in multiferroic materials [7], as well as for the measurement of the magnetization orientation using two- and three-dimensional vector magnetometry [2,8]. In the talk, the GME methodology will be introduced, its experimental implementation presented and recent developments discussed, such as data set optimization [9] and the detection and methodological incorporation of optical anisotropy [10], which is so far generally ignored in the realm of most magneto-optics measurements. The author acknowledges fruitful discussions with J.B. Gonzalez-Diaz, O. Idigoras, J.A. Arregi, and E. Bergaretxe on the topic of GME and magneto-optics in general. Funding from the Basque Government under Program No. PI2009-17 and the Spanish Ministry of Science and Education under Project No. MAT2009-07980 is acknowledged.

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References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

A. Berger and M. R. Pufall, Appl. Phys. Lett. 71, 965 (1997) A. Berger and M. R. Pufall, J. Appl. Phys. 85, 4583 (1999) K. Sato, Jpn. J. Appl. Phys. 20, 2403 (1981) W. S. Kim, M. Aderholz and W. Kleemann, Meas. Sci. Technol. 4, 1275 (1993) M. R. Pufall and A. Berger, J. Appl. Phys. 87, 5834 (2000) K. Mok, G. J. Kovacs, J. McCord, L. Li, M. Helm, and H. Schmidt, Phys. Rev. B 84, 094413 (2011) M. Bastjan, S.G. Singer, G. Neuber et al., Phys. Rev. B 77, 193105 (2008) K. Mok, N. Du and H. Schmidt, Rev. Sci. Inst. 82, 033112 (2011) J.A. Arregi, J.B. Gonzalez-Diaz, E. Bergaretxe, O. Idigoras, T. Unsal, and A. Berger, submitted to J. Appl. Phys. J.B. Gonzalez-Diaz, O. Idigoras, J.A. Arregi, E. Bergaretxe, and A. Berger, in preparation

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Conformation changes of man-made DNA nanostructures

7 Victoria Birkedal iNANO center, Aarhus University, NyMunkegade 118, Aarhus, Denmark vicb@inano.au.dk Nucleic acids form dynamical structures in living organism that have a given function. They are also nanosized materials that can be used in the lab for the construction of self-assembled twodimensional and three-dimensional nanostructures. Thus, complex man-made structures, such as tiles, rods, cages and more can now be realized using nucleic acids programmed molecular recognition through complementary base pairing. Through the structuresâ&#x20AC;&#x2122; design, it is also possible to introduce the possibility of movement and/or change of conformation, so that the structure is dynamical and can perform a given function. Here, we focus on two of those structures: a box made of DNA [1] and a DNA actuator [2]. The opening of the self assembled DNA box and the rolling motion of the DNA actuator are investigated by fluorescence resonance energy transfer (FRET) spectroscopy and microscopy. FRET spectroscopy is a very sensitive technique that is able to measure small changes in the distance between two fluorophores that are between ~3-7 nm apart. Thus, by labeling the DNA structures with a donor and an acceptor fluorophore, their conformational changes can be followed. Single molecule fluorescence microscopy allows for additional insight into complex and heterogeneous biomolecules [3]. Indeed, single molecule measurements permit to follow the conformational changes dynamics of each molecule independently. This gives information on the conformational heterogeneity and movement dynamics of the studied nanostructures and allows studying specific sub-populations within heterogeneous samples.

Figure 1: Schematic drawing of a DNA box structure with two DNA locks, fluorophore positions are shown with red and green stars [1].

The self-assembled DNA box, Figure 1, is made by folding a long single-stranded viral DNA genome in the desired shape with the help of hundreds of short DNA staple strands using the origami technique. It is a closed container 43x36x36 nm3 in size, whose lid can be opened with DNA keys [1]. A tight control of the box opening is important for potential applications such as the controlled release of a nanocargo. The DNA box is labeled with Cy3 and Cy5 fluorophores, which are placed so that closed and fully opened boxes have high and low FRET efficiency, respectively. We find that the closed boxes indeed show a FRET effect and that the measured value holds information about the local structure of the lid. Upon addition of all keys, no energy transfer between the two fluorophores is observed, indicating that the box opens fully. The lid opening with the help of several DNA keys can thus successfully be controlled.

Figure 2: Schematic drawing of a DNA actuator, made of two piston DNA strands A and B and a roller, R, the direction of movement is shown by the arrows on strand A and B (right panel) [2].

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The DNA actuator, Figure 2, is a man made DNA structure that could act as an extendable arm in a nanoscale assembly line. The actuator is composed of two pistons that can slide with respect to each other and the device can be locked in place in 11

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different states [2]. By attaching a donor and acceptor fluorophore on each of the two pistons respectively, we can follow the movement of the actuator at the nanometer scale. We find that the actuator can be switched from state to state with the help of DNA locking strands and that movement can be controlled with nanometer precision. Single molecule measurements allow for additional insight into how the DNA actuator is moving. Our studies allow gaining insight into and control of the movement of complex man-made DNA structures. References [1] [2] [3]

E. S. Andersen et al., Nature 459 (2009) 73-75. Z. Zhang et al., Angew. Chem. Int. Ed. 50 (2011) 3983-3987. V. Birkedal et al. Microscopy Research and Technique 74, (2011) pp.688-98.

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Graphene Photonics and Optoelectronics

9 Francesco Bonaccorso Engineering Department, Cambridge University, 9 JJ Thomson Avenue, Cambridge, UK Graphene has huge potential in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, the absence of a bandgap can be beneficial, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability [1]. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers [1]. Despite being a single atom thick, graphene can be optically visualized [2]. Its transmittance can be expressed in terms of the fine structure constant [3]. The linear dispersion of the Dirac electrons enables broadband applications [4,5,6,7]. Saturable absorption is observed as a consequence of Pauli blocking [7,8]. Chemical and physical treatments enable luminescence [1,9]. Broadband nonlinear photoluminescence is also possible following non-equilibrium excitation of untreated graphene layers [10,11,12]. Graphene-polymer composites prepared using wet chemistry [7,8,13] can be integrated in a fiber laser cavity, to generate ultrafast pulses and enable broadband tunability [7,8]. Grapheneâ&#x20AC;&#x2122;s suitability for high-speed photodetection was demonstrated in optical communication links operating at 10Gbits-1 [5]. By combining graphene with plasmonic nanostructures, the efficiency of graphene-based photodetectors can be increased by up to 20 times [14]. Wavelength and polarization selectivity can be achieved by employing nanostructures of different geometries [14]. I will give a thorough overview of the state of the art of graphene photonic and optoelectronic devices, outlining the major stumbling blocks and development opportunities. In the first part of the talk I will focus on solar cells where graphene can fulfill the following functions: as the transparent conductor window [15], antireflective material [16], photoactive material [17], channel for charge transport [18], and catalyst [19]. A variety of configurations have been demonstrated to date, ranging from silicon solar cells (fig 1a) [16], to polymer (fig 1b) [17] and dye-sensitized solar cells (fig 1c) [15,18,19]. I will also show how plasmonic nanostructures can be used to increase dramatically the light harvesting properties in solar cells [14]. In the second part of the talk I will turn to a broader consideration of graphene applications in other photonic and optoelectronics devices, such as electroluminescent devices (fig.1 d) [20], photodetectors (fig.1 d) [5,6,14], smart windows (fig.1 f) [1] and ultrafast lasers [7,8]. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

F. Bonaccorso, et al. Nat. Photon. 4, 611 (2010). C. Casiraghi, et al. Nano Lett. 7, 2711 (2007). R. R. Nair, et al. Science 320, 1308 (2008). M. Liu, et al. Nature 474, 64 (2011). T. Mueller, et al. Nat. Photon. 4, 297 (2010). Xia, et al. Nature Nanotech. 4, 839 (2009). Z. Sun, et al. ACS Nano 4, 803 (2010). T. Hasan, et al. Adv. Mat. 21,3874 (2009). T. Gokus et al. ACS Nano 3, 3963 (2009). W-T. Liu,, et al. Phys. Rev. B 82, 081408(R) (2010). RJ. Stohr, et al. Phys. Rev B 82, 121408(R) (2010).

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[12] [13] [14] [15] [16] [17] [18] [19] [20]

c.H. Lui, et al. Phys. Rev. Lett. 105, 127404 (2010). 13.T. Hasan, et al. Physica Status Solidi B, 247, 2953 (2010). T.J. Echtermeyer, et al. Nat. Commun.2, 458 (2011). X. Wang, L. Zhi, K. Mullen, Nano Lett. 2007, 8, 323. X. Li et al. Adv. Mater. 2010, 22, 2743. V.Yong, J. M. Tour, Small, 6, 313 (2009). N. Yang, et al. ACS Nano 2010, 4, 887. W. Hong, et al. Electrochem. Commun. 10, 1555 (2008). S. Essig, et al. Nano Lett. 10, 1589 (2010).

Figures

Figure 1: Schematics of (a) inorganic solar cell, (b) polymer solar cell, (c) dye-sensitized solar cell, (d) organic light emitting diode (e) photodetector and (f) smart window.

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Point defects in graphene systems

11 Ivan Brihuega Departamento de F铆sica de la Materia Condensada, Universidad Aut贸noma de Madrid, E-28049 Madrid, Spain ivan.brihuega@uam.es How does the presence of single atomic defects modify the properties of materials? Such a general and fundamental question is addressed by our work for atomic vacancies in graphene systems, where the presence of such defects is expected to have a dramatic impact in its properties due to graphene's pure bidimensionality. Introducing vacancies in graphene-like systems by irradiation has been shown to be an efficient method to vary its mechanical behavior, tune its electronic properties and even to induce magnetism in otherwise non-magnetic samples [1-3]. While the role played by these vacancies as single entities has been extensively addressed by theory [4-7], experimental data available refer to statistical properties of the whole heterogeneous collection of vacancies generated in the irradiation process [1-3]. In this talk I will show how we have overcome this limitation: we first created perfectly characterized single vacancies on graphene layers by Ar+ ion irradiation and then, using low temperature scanning tunneling microscopy (LT-STM), we individually investigated the impact of each of such vacancies in the electronic, structural and magnetic properties of several graphene systems [8-10].

Figure 1: a) Art illustration of a graphene layer atomically tailored by introducing single carbon vacancies. Vacancies are deliberately generated by irradiating the graphene layer with Ar ions (represented by red balls) and its impact in the electronic, structural and magnetic properties of the graphene layer is investigated at the atomic scale by means of a scanning tunneling microscope (represented by the cone-tip at the upper right corner). b) This 3D image (left panel), obtained with a home-made LT-STM, shows a single isolated atomic vacancy artificially created on a graphite surface. A sharp electronic resonance peak has been found on top of each individual vacancy (right panel), which can be associated with the generation of a magnetic moment in this pure carbon system. c) Left panel shows a 3D view of a single isolated vacancy created in the graphene/Pt(111) surface. Right panel corresponds to 6 K STS measurements of the LDOS on a C vacancy (blue circles) and on pristine graphene/Pt(111) showing the existence of a broad electronic resonance above the Fermi energy associated to single C vacancies in this system.

I will first show our results about the role of single isolated vacancies generated in a graphene layer weakly coupled with the substrate as it is the graphite surface [8]. Very recently, it has been predicted that individual carbon vacancies in graphite could even originate room temperature magnetism. Our LT-STM experiments, complemented by tight-binding calculations, reveal the presence of a sharp

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electronic resonance at the Fermi energy around each single graphite vacancy, which can be associated with the formation of local magnetic moments and implies a dramatic reduction of the charge carriers’ mobility. While vacancies in single layer graphene lead to magnetic couplings of arbitrary sign, our results show the possibility of inducing a macroscopic ferrimagnetic state in multilayered graphene just by randomly removing single C atoms. A fundamental question which naturally follows is: Will properties of this atomically tailored graphene survive in real devices after the unavoidable contact with other materials, in particular with metals? In the second part of the talk, I will show how we combined LT-STM studies with density functional theory calculations to address such a key question, demonstrating that even in weakly coupled graphene/metal systems, the presence of the metal has to be seriously taken into account in order to controllably tune graphene properties by locally modifying its structure [9]. In particular, we have demonstrated that while electronic properties of pristine graphene are basically preserved when adsorbed on Pt(111) surfaces, vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in freestanding graphene layers. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

P. Esquinazi, D. Spemann, R. Höhne, A. Setzer, K.-H. Han and T. Butz, Phys. Rev. Lett. 91, 227201 (2003). C. Gomez-Navarro et al., Nature Mater. 4, 534 (2005). A. V. Krasheninnikov and F. Banhart, Nature Materials 6, 723 (2007). V. M. Pereira, F. Guinea, J. M. Lopes dos Santos, N. M. R. Peres and A. H. Castro Neto, Phys. Rev. Lett. 96, 036801 (2006). P. O. Lehtinen, A. S. Foster, Y. C. Ma, A. V. Krasheninnikov and R. M. Nieminen , Phys. Rev. Lett. 93, 187202 (2004). J. J. Palacios, J. Fernández-Rossier and L. Brey, Phys Rev. B 77, 195428 (2008). O. V.Yazyev, Phys. Rev. Lett. 101, 037203 (2008). M. M. Ugeda, I. Brihuega, F. Guinea and J. M. Gómez-Rodríguez, Phys. Rev. Lett 104, 096804 (2010). M. M. Ugeda, D. Fernández-Torre, I. Brihuega, P. Pou, A. J. Martínez-Galera, R. Pérez and J. M. Gómez-Rodríguez. Phys. Rev. Lett 107, 116803 (2011). A.J. Martínez-Galera, I. Brihuega and J. M. Gómez-Rodríguez, Nano Letters 11, 3576 (2011).

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Combination of optical microtransmission and microphotoluminescence techniques for local characterization of rare earth doped glass microspheres D. Navarro-Urrios,1,2 M. Baselga,1 F. Ferrarese Lupi,1 L. L. Martín,3 C. Pérez-Rodríguez,3 I. R. Martín,3 C. Vasconcelos,4 and N. E. Capuj5 1

MIND-IN2UB, Dept. Electrònica, Universitat de Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain Catalan Institute of Nanotechnology (CIN2-CSIC), Campus UAB, Edifici CM3, 08193 Bellaterra, Spain 3 Departamento de Física Fundamental y Experimental, Electrónica y Sistemas and MALTA Consolider Team, Universidad de La Laguna, 38206 Tenerife, Spain 4 Department of Technological Sciences and Development, Campus de Ponta Delgada, Azores University, 9501-801 Ponta Delgada, Açores, Portugal 5 Departamento Física Básica, Universidad de La Laguna, 38206 Tenerife, Spain 2

dnavarro@icn.cat

Figure 1: Scheme of the combined µ-transmission and µ-PL setup. It is also shown an image of a microsphere taken with a CCD when the monochromator is in the zero order and the slit of the monochromator widely opened.

We present an optical characterization of single rare earth doped glass microspheres by means of an innovative experimental setup that combines µ-transmission and µphotoluminescence (µ-PL) measurements. The microspheres under study were fabricated with the method of G. R. Elliot et al. [1] from bulk borate glass doped with neodymium (Nd3+) ions. [2] The detection stage allows collecting light coming out from a reduced physical region around a lateral edge of the sphere, which reduces the spectral inhomogeneous broadening of the supported modes due to deviations from perfect sphericity. The experimental setup used for realizing µ-PL and µ-transmission measurements is schematized in Figure 1.

We demonstrate that, in µ-transmission, it is possible to obtain significant WGM coupling efficiency even if the external beam is in free space. In addition, a robust oscillating-like signal is clearly revealed, which we explain in terms of excitation of a closed polygonal trajectory experimenting at least 5 internal reflections. By comparing the results of both techniques for a given single microsphere we TR polarisation demonstrate their consistency and complementarity for achieving a more extensive characterization of its optical and geometrical properties. 600 500 300 200 100

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Figure 2: Schematic drawing of a DNA actuator, made of two piston DNA strands A and B and a roller, R, the direction of movement is shown by the arrows on strand A and B (right panel) [2].

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To illustrate the above, on Figure 2 we show the comparison of the µ-transmission (already normalized by the transmission signal obtained without microsphere) and µ-PL spectra of a microsphere with a radius of R=9.5 µm for TR (orthogonal to the sphere surface) and TM (tangential to the sphere surface) polarizations. The µ-transmission spectra (black curves)

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consist on oscillating-like signals with sharp signal dips superimposed to them that are associated to WGM. On the other hand, the µ-PL spectra, which are generated by the radiative recombination of optically pumped Nd3+ ions, are composed by an offset signal generated by ions that do not couple to microsphere modes and sharp peaks associated to PL signal exciting the WGM of the microcavity. It is remarkable the agreement in the WGM spectral positions showed by both techniques for both polarizations, which indicates that there is no sizeable effect on the microsphere modal structure due to the presence of the pump over the microsphere. Finally, we discuss how these results may enhance the potentiality of light emitting isolated spheres for sensing applications, since the combination of both techniques can provide trustful information of refractive index changes on the sphere surroundings. The authors are grateful to Ministerio de Ciencia e Innovación of Spain (MICCIN) under The National Program of Materials (MAT2010-21270-C04-02), The Consolider-Ingenio 2010 Program (MALTA CSD2007-0045), to the EU-FEDER funds and to FPI of Gobierno de Canarias for their financial support. D. N-U. thanks the finantial support of The Generalitat de Catalunya through the Beatriu de Pinòs program. References [1] [2]

G. R. Elliott, D. W. Hewak, G. S. Murugan and J. S. Wilkinson, Optics Express, 15 (2007) 17542. L. L.Martin, P. Haro-Gonzalez, I. R. Martin, D. Navarro-Urrios, D. Alonso, C. Perez-Rodriguez, D. Jaque, and N. E. Capuj, Optics Letters 36 (2011) 615.

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Virus scaffolds as Enzyme Nano-Carriers (ENCs)

15 Daniela Cardinale1, Noëlle Carette1, Jane Besong2, Amandine Barra1, Jocelyne Walter1, Thierry Delaunay1, Christophe Demaille3, Agnés Anne3, Olivier Courjean4, Nicolas Mano4, Jean-Paul Salvetat4, Jean-Pierre Aimé5, Kristiina Mäkinen2, Thierry Michon1. 1 INRA, Univ. Bordeaux Segalen, UMR 1090 GDPP, IBVM Virologie, 71 Av. Edouard Bourlaux, B.P. 81, 33883 Villenave d’Ornon, France. 2University of Helsinki, Applied Biochemistry and Molecular Biology, Department of Food and Environmental Sciences, P.O.Box 27 (Street: Latokartanonkaari 11), Finland; 2 Laboratoire d’Electrochimie Moléculaire, UMR CNRS – P7 7591, Université Paris Diderot – Paris 7, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Paris cedex 13, France. 3 CRPP, Centre de Recherche Paul Pascal, 115 Av. Schweitzer, 33600 Pessac, France. 4 CPMOH, Centre de Physique Moléculaire Optique et Hertzienne, UMR5798,Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence, France.

daniela.cardinale@bordeaux.inra.fr Nature offers to the nanotechnologist exquisite precisely defined nanometer-sized objects. Viruses are well-ordered structures formed by a self-association of capsid proteins monomers that can be easily modified by genetic engineering or by chemistry. Engineered bacterial, animal and plant viruses have been already used for instance as biosensors, nanoreactors or high throughput screening tools. Our aim is to use plant viruses as enzymes supports to create a new experimental tool mimicking in vivo enzymatic cascade reactions at the nanoscale level. The association of collaborating enzymes in supramolecular structures enables metabolic processes to be performed more efficiently, accelerating reactions rates and preventing the diffusion of intermediates in the cell medium. The project’s outcomes will serve the technology of enzymatically assisted catalysis in organic synthesis with potential applications for the technology of microreactors and biosensors. Viruses applied as Enzyme's NanoCarriers (ENCs) will also offer the opportunity to study enzymatic processes at the level of one single or few molecules. Thanks to an innovative AFM/SECM technique, that plans to fabricate a “nanocavity” microelectrode at the tip of an AFM probe, it will be possible to confine clustered enzymes and to measure de final activity of few enzymes molecules. Two model enzymes will be used to build artificial redox cascades: the lipase B (CalB) from Candida antarctica and the glucose oxidase (GOX) from Penicillum amagasakiense. In order to interface virus and enzymes we selected 3 peptides which bind specifically to one end of PVA (Potato virus A) our model virus. These peptides were cloned at the N-terminus of CalB (lipase B from Candida Antarctica). AFM and TEM images show clustering of the modified enzymes to the extremity of the virus.

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Probing confined photons in nanoscale disordered media from inside

17 Rémi Carminati Institut Langevin, ESPCI ParisTech, CNRS 75231 Paris Cedex 05, France remi.carminati@espci.fr A substantial effort is devoted to the understanding of light scattering in disordered materials, both for fundamental studies in mesoscopic physics and for applications (imaging with diffuse light, design of novel photonic materials). Standard measurements involve averaged transmitted or reflected intensity, or fluctuations (speckles). In this talk we show that probing photonic properties of nanoscale disordered media from inside reveals important features, in particular the interplay between multiple scattering and near-field interactions. This can be achieved by studying the fluorescence dynamics of nanosources placed inside the medium. Modifications of the spontaneous decay rate (or fluorescence lifetime) of dipole nanosources can be understood from changes in the local density of photonic states (LDOS). The statistical distribution of the decay rate (or LDOS) in a disordered medium structured at the nanoscale exhibits a long tail, giving rise to large fluctuations. The long tail corresponds to substantial changes in the LDOS (or equivalently to large Purcell factors) produced by rare events. The analysis of the statistical distributions reveals different interaction regimes [1,2], and puts forward the influence of short-range Figure 1: Normalized variance of the LDOS measured on near-field scattering [3]. Experiments performed on disordered gold films with different surface fractions. The peak in the LDOS fluctuations is a signature of localized disordered metallic films [4] reveal the existence of plasmon modes. The insets show TEM images of a few spatially localized modes produced by the interplay samples. Adapted from [4]. between disorder and plasmon resonances (see Fig. 1). Large Purcell factors are also observed in strongly scattering dielectric powders, and can be attributed to confined photonic modes produced by near-field scattering [5]. Acknowledgments These studies were made possible thanks to the work of E. Castanié, A. Cazé, V. Krachmalnicoff, R. Pierrat and Y. De Wilde at ESPCI Paristech. The measurements of Purcell factors in volume scattering samples are due to P. Bondareff, B. Habert, R. Sapienza and N.F. van Hulst at ICFO Barcelona. References [1] [2] [3] [4] [5]

R. Pierrat and R. Carminati, Phys. Rev. A 81, 063802 (2010). R. Carminati and J.J. Sáenz, Phys. Rev. Lett. 102, 093902 (2009). A. Cazé, R. Pierrat and R. Carminati, , Phys. Rev. A 82, 043823( 2010). V. Krachmalnicoff, E. Castanié, Y. De Wilde and R. Carminati, Phys. Rev. Lett. 105, 183901 (2010). R. Sapienza, P. Bondareff, R. Pierrat, B. Habert, R. Carminati and N.F. van Hulst, Phys. Rev. Lett. 106, 163902 (2011).

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Doping and sensing in silicon nanowires

19 X. Cartoixà1, A. Miranda-Durán2, R. Rurali2 1

Departament d’Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain 2 Institut de Ciència de Materials de Barcelona-ICMAB (CSIC), 08193 Bellaterra, Barcelona, Spain Xavier.Cartoixa@uab.es

The theoretical study of dopant properties in one-dimensional (1D) semiconductor systems, such as passivated nanowires (NWs), is hindered by the inadequacy of the well-established Zhang-Northrup formalism [1] to deal with cases where the chemical potential of the NW constituents is not well defined. In addition, dopant properties demand the computation of total energies of systems with a net charge, which have to be compensated by a background jellium when using periodic boundary conditions, and corrected after that for spurious electrostatic interactions. Again, the procedure to make that correction—well established in bulk—is ill-defined for 1D systems. We will present a recently proposed framework for the calculation of formation energies of neutral and charged point defects in 1D systems [2] which successfully overcomes the aforementioned difficulties. We apply this formalism to three case studies with potential high impact for future nanoelectronics applications.

Figure 2: Cross-section view of a 1.0 nm <111> SiNW with CH3 passivation (see Ref. [4])

Surface segregation of dopants in CH3 passivated SiNWs ― It was soon recognized that surface segregation was one of the most important limiting factors in the doping efficiency of thin SiNWs [3]. In presence of dangling bonds, dopant impurities are driven to the surface where they form electrical inactive complexes with the surface defects. We revise this scenario in the case of the novel methyl-passivated SiNWs (Fig. 2) that have been demonstrated experimentally recently [4], whose stability in air is believed to be superior with respect to more conventional H passivated wires.

Figure 3: (a) Formation energy of the neutral (0) and the negatively charged (-1) Al substitutional in a <111> SiNW. The crossing μe signals the ionization energy. (b) Formation energy diagram for three different SiNW diameters.

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Al solubility ― We have studied Al point defects in 1 and 1.5 nm SiNWs grown along the <110> and <111> axes. Two reasons make Al impurities a very interesting case study: (i) group III elements can be efficient p-type dopants for Si, and the use of Al for doping in nanowires has indeed been proposed [5]; (ii) Al has proven to be a feasible alternative to Au as a catalyst for the epitaxial growth of SiNWs [6], having the considerable advantage of not introducing undesired midgap states that can act as traps and requiring lower growth temperatures. We find that, as in bulk, substitutionals are preferred over interstitials. However, although Al continues to behave as an acceptor in the SiNWs, the activation energy is strongly increased due to the quantum confinement effect (Fig. 3). Also, we predict that substrate bias can control the

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solubility of the Al impurity.

Molecular doping and gas sensing ― As tradiƟonal substitutional dopants are ineffective in thin NWs due to dielectric and quantum confinement effects, we must look for alternative avenues. Surface adsorption by select molecular species can provide the necessary charge transfer (Fig. 1), as we have recently shown [7]. This will also be used to explain the observed gas sensing properties of porous Si [8]. We acknowledge the financial support of the Spanish Ministerio de Ciencia e Innovación under contract No. TEC2009-06986. References: [1] [2] [3] [4] [5] [6] [7] [8]

Figure 1: Band structure and projected density of states for a 1.5 nm SiNW with an adsorbed ammonia molecule.

S. B. Zhang and J. E. Northrup, Phys. Rev. Lett. 67 (1991) 2339. R. Rurali and X. Cartoixà, Nano Lett., 9 (2009) 975–979. M. V. Fernández-Serra, Ch. Adessi, and X. Blase, Phys. Rev. Lett., 96 (2006) 166805. H. Haick, P. T. Hurley, A. I. Hochbaum, P. Yang, and N. S. Lewis, J. Am. Chem. Soc., 128 (2006) 8990. E. Durgun, N. Akman, C. Ataca, and S. Ciraci, Phys. Rev. B, 76 (2007) 245323. Y. Wang, V. Schmidt, S. Senz, S. and U. Gösele, Nat. Nanotechnol., 1 (2006) 186. A. Miranda-Duran, X. Cartoixà, M. C. Irisson and R. Rurali, Nano Lett., 10 (2010) 3590. Garrone, E.; Geobaldo, F.; Rivolo, P.; et al., Adv. Mater. 17 (2005) 528.

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Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2 Andres Castellanos-Gomez1,2, Menno Poot2, Albert Amor-Amoros1, Gary A. Steele2, Herre S.J. van der Zant2, Nicolás Agraït1,3 and Gabino Rubio-Bollinger1 1

Departamento de Física de la Materia Condensada (C–III). Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid, Spain. 2 Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. 3 Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid, Spain. a.castellanosgomez@tudelft.nl Two-dimensional crystals are promising materials for nextgeneration flexible electronic devices. Indeed graphene, which exhibits a very high mobility, has been recently applied as transparent and flexible electrode [1]. The lack of a bandgap in pristine graphene, however, hampers its possible application in semiconducting devices. Up to now, two different strategies have been employed to fabricate semiconducting two-dimensional crystals. While the first one relies on opening a bandgap in graphene through topdown engineering [2] or chemical modification, [3] the second one involves the use of another two-dimensional Figure 1: Contact mode AFM topography of a crystal with a large intrinsic bandgap. [4,5] Atomically thin 3-4.2 nm thick MoS2 flake (5-7 layers thick). (inset) Topographic line profile acquired along crystals of the semiconducting transition metal the dashed line. dichalcogenide molybdenum disulphide (MoS2) have emerged as a very interesting substitute/complement to graphene in semiconducting applications due to its large intrinsic bandgap of 1.8 eV and high mobility μ > 200 cm2V-1s-1. Nevertheless, the mechanical properties of this nanomaterial, which will dictate their applicability in flexible electronic applications, remain unexplored so far. Figure 2: (a) Schematic diagram of the nanoscopic bending test experiment carried out on a freely suspended MoS2 nanosheet. When a displacement of the sample is made by the AFM scanning piezotube, both the cantilever and the flake are deformed Using both the known piezo displacement and the measured laser deflection, both the force F and deflection δ can be extracted. (b) Force vs. deflection traces measured at the center of the suspended part of MoS2 nanosheets with 5, 10 and 20 layers in thickness. The slope of the traces around zero deflection is marked by a dotted line.

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We study the elastic deformation of freely suspended MoS2 nanosheets (Figure 1) by means of a nanoscopic version of a bending test experiment, carried out with the tip of an atomic force microscope (Figure 2a). The force vs. deformation traces show a unique thickness dependent non-linearity (Figure 2b) that can be accounted for by a continuum mechanics model in which the nanosheets are considered as elastic membranes under an initial pre-tension and with a non-negligible bending rigidity. Our measurements enable us to determine mechanical properties of

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MoS2 nanosheets such as the Young’s Modulus and the initial pre-tension. The Young’s modulus is extremely high (0.30 TPa), comparable to the one found in exfoliated graphene, and the deflections are reversible up to tens of nanometers. References [1] [2] [3] [4] [5]

K. Kim, Y. Zhao, H. Jang, S. Lee, J. Kim, J. Ahn, P. Kim, J. Choi, and B. Hong, Nature 7230 (2009) 706. M. Han, B. Özyilmaz, Y. Zhang, and P. Kim, Physical Review Letters 20 (2007) 206805. X. Li, X. Wang, L. Zhang, S. Lee, and H. Dai, Science 5867 (2008) 1229. A. Castellanos-Gomez, N. Agrait, and G. Rubio-Bollinger, Applied Physics Letters 21 (2010) 213116. B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, Nature Nanotechnology 3 (2011) 147.

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Optimizing light harvesting for high magneto-optical performance in metal-dielectric magnetoplasmonic nanodiscs Alfonso Cebollada, Juan Carlos Banthí, David Meneses, Fernando García, María Ujué González, Antonio García-Martín, and Gaspar Armelles IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760 Tres Cantos, Madrid, Spain alfonso@imm.cnm.csic.es The term magnetoplasmon, or magnetoplasma surface wave, was first introduced in the early 70’s, motivated by a renovated interest in surface plasmons in metals and degenerate semiconductors [1,2]. At that time, the effect of an external magnetic field on the dielectric function of a solid, and as a direct consequence on the surface plasmons, seeded a number of investigations which in the case of semiconductor structures continues to our days. Later in the 80’s [3,4,5,6,7] and 90’s [8,9] different groups studied the effect of bulk and surface plasmon resonances respectively on the magnetooptical (MO) activity of a number of materials systems. Nowadays, the phenomenology associated to systems where plasmonic and MO properties coexist has become an active area of investigation, and an increasing number of research groups have explored this phenomenology from the experimental and theoretical viewpoints.The so called magneto-plasmonic systems have opened new routes for the development for example of higher performance gas and biosensing platforms [10,11] as well as the exploitation of non-reciprocal effects [12] in devices with potential applications in the telecomunications area. In magnetoplasmonic structures, magnetic and plasmonic properties are intertwined, allowing for example plasmonic properties to become tunable upon de application of a magnetic field (active plasmonics) [13], or the MO effects to be largely increased by plasmon resonance excitation, as a consequence of the enhancement of the electromagnetic (EM) field in the MO active component of the structure [14]. In this last case, the study of the enhanced MO activity in structures with subwavelength dimensions is especially interesting since they may be viewed as nanoantennas in the visible range with MO functionalities. The light harvesting properties of these systems upon plasmon resonance excitation bring as a consequence an enhanced EM field in its interior, and more interestingly in the region where the MO active component is present. At this stage, optimizing the EM field distribution within the structure by maximizing it in the MO components region while simultaneously minimizing it in all the other, non MO active, lossy components, will allow for the development of novel systems with even larger MO activity with reduced optical losses, becoming an alternative to state of the art dielectric MO materials, like garnets. In this presentation, our current understanding of this phenomenology and our approach to face this problem will be presented. We will show how the insertion of a dielectric layer in Au/Co/Au magnetoplasmonic nanodisks induces an EM field Figure 1: Sketch of the fabricated structures, and representative AFM redistribution in such a way to image of one of them.

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concentrate it in the regions of interest of the nanostructure. In figure 1 we show the nanodisk structures fabricated by hole mask colloidal lithography and evaporation. Two structures, with a SiO2 layer attached to the upper and lower Au layer were fabricated respectively, together with a fully metallic structure, i.e. without SiO2. Figure 2 shows as an example experimental and theoretical optical extinction and MO activity for the system with the SiO2 layer attached to the upper Au layer and for the fully metallic structure. The metallo-dielectric system exhibits large MO activity and low optical extinction in the high wavelength range (around 780 nm). It will be demonstrated how this is due to the specific EM field redistribution at this wavelength, controlled by the insertion of the dielectric layer.

Figure 2: Experimental and theoretical optical extinction and MO activity for the structure with the SiO2 layer attached to the upper Au layer (continuous lines) and for the fully metallic structure (dashed lines).

Acknowledgements The authors acknowledge funding support from the EU (NMP3-SL-2008-214107-Nanomagma), the Spanish MICINN (“FUNCOAT” CONSOLIDER INGENIO 2010 CSD2008-00023, MAGPLAS MAT200806765-C02-01/NAN and PLASMAR MAT2010-10123-E) and the Comunidad de Madrid (“NANOBIOMAGNET”, S2009/MAT-1726 and “MICROSERES-CM”, S2009/ TIC-1476, and JAE Doc fellowship for D. Meneses-Rodríguez). References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]

K.W.Chiu and J.J.Quinn, Physical Review 5 (1972) 4707. E.D.Palik et al., Physics Letters 45A (1973) 143. W.Reim et al, JAP 55 (1984) 2155. H.Feil and C.Haas, PRL 58 (1987) 65. T.Katayama et al., PRL 60 (1988) 1426. McGahamn et al APL 55 (1989) 2479. Reim and Weller IEEE Trans Magn 25 (1989) 3752. V.I.Safarov et al, PRL 73 (1994) 3584. C.Herman et al, PRB 64 (2001) 235422. B.Sepúlveda et al., Opt. Lett. 31 (2006) 1085. M.G.Manera et al., Journal of Materials Chemistry 21 (2011) 16049. J.B.González-Díaz et al., Phys. Rev. B 76 (2007) 153402. V.V.Temnov et al., Nature Photonics, 4 (2010) 107. G.Armelles et al., J. Opt. A: Pure Appl. Opt. 11 (2009) 114023.

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Application of plasma technologies to biological interface design

25 M. Perez Roldan, A. Ruiz, , G. Ceccone, P. Colpo, Fr. Rossi European Commission, Joint Research Centre Ispra (Italy) Francois.Rossi@jrc.ec.europa.eu, pascal.colpo@jrc.ec.europa.eu

Figure 1: Plasma polymerised Acrylic acid nanostructure in a PEO-Like background.

One of the major challenges for the development of bio interfaces relies on the ability to design solid surfaces with controlled interactions with the biological entities. Surface functionalisation techniques can provide those biointerfaces appropriate physico-chemical properties enabling the control of the conformation and activity of the immobilized biomolecules. The subsequent technological step is the combination of different biofunctions in micro- and nano-patterns on the surfaces. For instance, structuring the surface in adhesive and non adhesive zone in order to preferentially guide the cell growth is one of the most promising tools for the development of â&#x20AC;&#x2DC;cell on a chipâ&#x20AC;&#x2122; devices and for tissue engineering. The requirement of further integration and the study of the special behaviour of the biomolecules interacting with nanostructures have been the two main motivations for the development of submicron patterning techniques. Plasma assisted deposition techniques are interesting methods to produce functionalized surfaces with controlled micro- and nano-patterns: they provide high-level functionality with good stability on different substrates and are compatible with different micro- and nano-patterning techniques. In this work we show some examples of micro- and nanofunctional surfaces provided by plasma processes in combination with Electron beam lithography, proteins micro-contact printing and micro-spotting, and their application as platforms for cell cultures and biosensing.

Figure 2: Human Umbilical Cord Blood Neural Stem Cell micro patterning.

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Nanopatterned surfaces were produced by a spatial arrangement of different functional domains by a combination of plasma polymer and E-beam lithography techniques. In particular bio-adhesive nano-spots in a PEOlike anti-fouling matrix have been produced (figure 1). We show that these chemical nano-patterns are able to immobilize proteins selectively in the adhesive nanodomains, leaving the anti-fouling matrix clear of biomolecules. We show with different methods (SPR and AFM) that nano-patterned surface constrains the immobilization of the antibodies in a biological reactive

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configuration, thus significantly improving the surface interaction as compared to more conventional non-patterned surfaces. Two methods for protein patterning have been used as platform for cell patterning. Microcontact contact printing has been used as technique to transfer fibronectin through conformal contact, while piezoelectric deposition has been used as non-contact technique for producing arrays of fibronectin. Plasma deposited Poly(ethylene) oxide-like, PEO-like films have been used as non-fouling background to achieve the bioadhesive / biorepellent surface contrast. Both methods allow the direct fabrication of protein arrays on a non-fouling substrate and the formation of a stem cell pattern (figure 2). Microcontact printing produced fully packed homogeneous fibronectin patterns, much denser than microspotting patterns. In microspotting, the density of the protein layer was lower, but the immunorecognition of fibronectin targeted antibodies, as well as the cell density on the fibronectin spots could achieve similar levels to microcontact printing, thus were equally functional in both tested methods.

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Epitaxial graphene on metals and hybrid systems

27 Johann Coraux Institut NĂŠel, CNRS & UniversitĂŠ Joseph Fourier, 25 rue des Martyrs, Grenoble Cedex 9, 38042, France A number of transition metals may serve a supports and catalysts for the growth of epitaxial graphene. In the last few years synthesis routes which were historically parallel are converging: on one hand, preparation under ultra-clean conditions, namely under ultra-high vacuum and at the surface of single crystal metals; on the other hand, growth under pressures approaching atmospheric conditions, at the surface of metallic thin films. In both cases graphene layers having high quality can be obtained. The first approach delivers model systems especially suited to fine surface science studies. The second approach is motivated by the prospect for mass production of graphene. I will present our recent studies on a particular graphene/metal system which is a case study for graphene weakly interacting on its substrate, graphene/Ir(111), which we have been revisiting since 2007 and allows for the preparation of ultra-high quality graphene [1-5]. I will show that van der Waals bonding, modulated by a slight tendency to covalent bonding, ensures cohesion in this system [6]. I will then present our recent studies devoted to the deposit of metals on graphene/Ir(111), which leads to ordered two-dimensional arrays of magnetic nanoclusters [7] or ultra-thin magnetic films intercalated between graphene and its metallic substrate [8]. References [1] [2] [3] [4] [5] [6] [7] [8]

J. Coraux et al. Nano Lett. 8, 565 (2008). J. Coraux et al., New J. Phys., 11, 023006 (2009). R. van Gastel et al., Appl. Phys. Lett. 95, 121901 (2009). H. Hattab et al., Appl. Phys. Lett. 98, 141903 (2011). C. Vo-Van, et al., Appl. Phys. Lett. 98, .181903 (2011). C. Busse, et al., Phys. Rev. Lett. 107, 036101 (2011). A. T. N'Diaye et al., New J. Phys. 11, 103045 (2009). C. Vo-Van et al., Appl. Phys. Lett., in press. J. Coraux, A. T. N'Diaye, N. Rougemaille, unpublished.

Figures

Figure 1: (a) Side views of the structure (top), non local correlation binding energy density (middle), and charge transfer (bottom) for graphene/Ir(111), as derived from density functional theory calculations including van der Waals interactions. (b) Total electron yield from Co rich nanoclusters on graphene/Ir(111), across the L2,3 Co absorption edges for left and right circularly polarized X-rays at 5 T and 10 K (top), dichroic signal for X-rays impinging the sample perpendicular and inclined (bottom). (c) Scanning tunnelling microscopy topograph (90Ă&#x2014;50 nm2) of the Co rich clusters on graphene/Ir(111).

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Probing the nuclear spin of a single donor in Silicon nanotransistors

29 F. Delgado(1,2) and J. Fernandez-Rossier(1,2) (1)

INL | International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, 4715-330 Braga, Portugal (2) Depart. de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, 03690 Alicante, Spain Detection of a single nuclear spin constitutes an outstanding problem in different fields of physics such as quantum computing or magnetic imaging. Here we show that the energy levels of a single nuclear spin can be measured by means of a tunneling current [1]. As an example, we consider electronic transport through the single donor level of a Bismuth dopant in a Silicon nanotransistor, both in the sequential and in the cotunneling regimes, which has already been experimentally demonstrated [2,3]. In the sequential regime case, the dI/dV curve yields the single electron spectral function, while in the cotunneling regime, it provides information about the electronic spin spectral function [4]. The hyperﬁne coupling to the nuclear spin results in a modiﬁcation of the electronic spin spectral function which, in turn, could be probed by Inelastic Electron Tunneling Spectroscopy (IETS)[1,4-5], provided that the spectral resolution is high enough. We find that the hyperfine coupling opens new transport channels which can be resolved at experimentally accessible temperatures. Our simulations also evince that IETS yields information about the occupations of the nuclear spin states, paving the way towards transport-detected single nuclear spin resonance. References [1] [2] [3] [4] [5]

F. Delgado and J. Fernández-Rossier, Phys. Rev. Lett. 107, 076804 (2011). G. P. Lansbergen et al., Nano Letters 10, 455 (2010). K. Y. Tan et al., et al., Nano Letters 10, 11 (2010). J. Fernández-Rossier, Phys. Rev. Lett. 102, 256802 (2009). F. Delgado, J.J. Palacios, and J. Fernández-Rossier, Phys. Rev. Lett. 104, 026601 (2010)

Figures

Figure 1: Energy spectrum of 209Bi in Silicon as a function of applied field and the corresponding d2I/dV 2 spectra at T = 10mK. Spectra for different fields from 0 (black line) to 0.6T (brown line) are shown shifted vertically for clarity.

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A time-dependent view of electronic excitations in the nanoscale

31 Ricardo Díez Muiño Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU, San Sebastián, Spain, and Donostia International Physics Center DIPC, San Sebastián, Spain Femtosecond and subfemtosecond time scales typically rule electron dynamics in low-dimensional metallic systems. Recent advance in experimental techniques permits now remarkable precision in the description of these processes. In particular, shorter time scales, smaller system sizes, and spindependent effects are current targets of interest. In this lecture, we will review some of the distinct aspects that define electron dynamics in the nanoscale, focusing into confinement effects [1]. Using density functional theory and its time-dependent extension, we will show that the screening of localized charges in metal clusters and surfaces is created locally in the attosecond time scale, while collective excitations transfer the perturbation to larger distances in longer time scales. We will also briefly discuss the elastic width of resonances in excited alkali adsorbates on surfaces and the electron – electron scattering in several metallic systems of nanometer size. In addition, we will discuss the role of electron excitations in a different context, namely the elementary reactive processes that take place at metal surfaces [2]. Over the last years, the combination of experimental molecular-beam techniques and refined theoretical calculations based on ab-initio methods have led research on this field to a new stage, in which detailed investigations of the kinetics and dynamics of molecular reactivity at surfaces are possible. The possible relevance of non-adiabatic effects in these processes, as well as the time scale in which the different energy dissipation channels play a role will be discussed. References [1] [2]

R. Díez Muiño, D. Sánchez-Portal, V. M. Silkin, E. V. Chulkov, and P. M. Echenique, PNAS 108, 971 (2011). J.I. Juaristi, M. Alducin, R. Díez Muiño, H.F. Busnengo and A. Salin, Phys. Rev. Lett. 100, 116102 (2008).

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Distorting graphene through mechanics and edge chemistry

33 Chris Ewels1, V. Ivanovskaya1, Ph. Wagner1, A. Yaya1, A. Zobelli2, M. I. Heggie3, P. R. Briddon4 1

Institute of Materials, CNRS, University of Nantes, France 2 LPS, UniversitĂŠ Paris Sud, Orsay, France 3 Chemistry Department, University of Sussex, Brighton, UK 4 University of Newcastle Upon Tyne, UK In this talk we consider examples where density functional modelling allows detailed predictions of changes in structural, electronic, mechanical and chemical behaviour of graphene sheets in the presence of intrinsic and extrinsic point and line defects, opening the way to custom design of graphene properties through controlled chemistry. Interface formation in three-dimensional crystal lattices involves well characterised processes such as rebonding and rehybridisation, localised strain and dislocation formation. In contrast two dimensional crystal lattices, of which graphene is the archetype, are terminated by lines, and the additional available dimension opens up new topological interfacial possibilities. We show via DFT calculations that graphene sheet edges can adopt a range of topological distortions depending on their nature. Rehybridisation, local bond reordering, chemical functionalisation with bulky, charged, or multi-functional groups can lead to edge buckling to relieve strain [1], folding, rolling [2] and even tube formation [3]. As a result careful chemical control of sheet edge functionalisation allows radical modification of ribbon electronic, mechanical and chemical properties, for example reducing the Youngâ&#x20AC;&#x2122;s modulus of thinner ribbons by up to 40%.

After one-dimensional strain relief at edges we next examine the importance of lattice strain when considering point defect behaviour, and explore the possibilities for formation and glide of dislocation dipoles at vacancy sites [4]. Finally we show how the mechanical constraints of the graphene lattice can lead to new chemistry, taking the example of gas absorption on graphene surfaces [5]. References [1] [2] [3] [4] [5]

Ph. Wagner, C. Ewels, V. V. Ivanovskaya, P. R. Briddon, A. Pateau, B. Humbert, Phys. Rev. B 84 (13) 134110 (2011). V. V. Ivanovskaya, Ph. Wagner, A. Zobelli, I. Suarez-Martinez, A. Yaya, C. P. Ewels, accepted (Proc. GraphITA 2011, Wiley, 2011). V. V. Ivanovskaya, A. Zobelli, Ph. Wagner, M. Heggie, P. R. Briddon, M. J. Rayson, C. P. Ewels, Phys. Rev. Lett. 107, 065502 (2011). C. P. Ewels, V. V. Ivanovskaya, M. I. Heggie, C. D. Latham, U. Bangert, submitted (2011). A. Yaya, C. P. Ewels, I. Suarez-Martinez, Ph. Wagner, S. Lefrant, A. Okotrub, L. Bulusheva, P. R. Briddon, Phys. Rev. B 83 (4), 045411 (2011).

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Atomic-scale engineering of electrodes for single-molecule contacts

35 T. Frederiksen1, G. Schull2, A. Arnau1,3,4, D. Sánchez-Portal1,3, R. Berndt5 1

Donostia International Physics Center (DIPC), Donostia-San Sebastián, Spain 2 Institut de Physique et Chimie des Materiaux de Strasbourg, UMR 7504 (CNRS - Universite de Strasbourg), Strasbourg, France 3 Centro de Fisica de Materiales CSIC-UPV/EHU, Materials Physics Center MPC, Donostia-San Sebastián, Spain 4 Depto. Física de Materiales UPV/EHU, Facultad de Química, Donostia-San Sebastián, Spain 5 Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Germany The transport of charge through a conducting material depends on the intrinsic ability of the material to conduct current and on the charge injection efficiency at the contacts between the conductor and the electrodes carrying current to and from the material. To explore if this remains valid down to the limit of single-molecule junctions, experiments with atomic-scale control of the junction geometry is required. Here we present a method for probing the current through a single C60 molecule while changing, one by one, the number of atoms in the electrode that are in contact with the molecule [1]. We show quantitatively that the contact geometry has a strong influence on the conductance. We also find a crossover from a regime in which the conductance is limited by charge injection at the contact to a regime in which the conductance is limited by scattering at the molecule. Thus, the concepts of ‘good’ and ‘bad’ contacts, commonly used in macro- and mesoscopic physics, can also be applied at the molecular scale. To interpret the experimental observations we performed electronic structure calculations for different contacting configurations to a C60 molecule sandwiched between Cu(111) electrodes [1,2]. The calculations reproduce the experimental behavior and explain the crossover from cluster-size limited to molecule limited transport regimes in terms of projected density of states and position of the molecular resonances.

References [1] [2]

G. Schull, T. Frederiksen, A. Arnau, D. Sanchez-Portal, and R. Berndt, Nature Nanotechnology 6, 23-27 (2011). G. Schull, T. Frederiksen, M. Brandbyge, and R. Berndt, Phys. Rev. Lett. 103, 206803 (2009).

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Hybrid photonic-plasmonic crystals based on self-assembled structures

37 A. García-Martín1, M. López-García2, J. F. Galisteo-López2, A. Blanco2, and C. López2 1

IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), c/Isaac Newton 8, PTM, Tres Cantos, 28760 Madrid, Spain 2 Instituto de Ciencia de Materiales de Madrid (ICMM)-CSIC, C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain a.garcia.martin@csic.es

The fields of photonic crystals and plasmonics have been actively explored over the past two decades as a means to exert control on light propagation and emission in ways not permitted by conventional materials. While photonic crystals have achieved unprecendent control over the guiding and generation of light, the nanoscale confinement of electromagnetic radiation allowed by metallic nanostructured systems remains unparalleled. Recently, the possibility of combining the two fields in hybrid metallodielectric structures has paved the way to strongly confine electromagnetic radiation while avoiding losses associated with metals [1,2]. We will present recent results regarding the possibility of fabricating hybrid photonic-plasmonic systems by means of self-assembly techniques. In particular, we have studied photonic crystals in the form of 2D arrays of organic spheres containing light emitters, coupled to surface plasmon polariton supporting substrates. Combining numerical simulations and a thorough optical characterization, an in depth understanding of the way light propagates in this kind of structures has been obtained. Beyond a complete study of the optical properties of passive systems[3], the possibility of strongly modifying the spontaneous emission of the internal light sources will be presented [4]. Other aspects of these systems, such as the possibility of fine tuning their optical response by means of a nanometer control of the dielectric components, will be discussed [5].

References [1] [2] [3] [4] [5]

J. Grandidier, S. Massenot, G. Colas des Francs, A. Bouhelier, J.-C. Weeber, L. Markey, A. Dereux, J. Renger, M. U. González, and R. Quidant, Phys. Rev. B 78, (2008) 245419 R.F. Oulton, V. J. Sorger, V. J. Zentgraf, R.M. Ma, C. Gladden, L. Dai, G. Bartal, X. Zhang, Nature 461, (2009) 629 J. F. Galisteo-Lopez, M. Lopez-Garcia, C. Lopez, and A. Garcia-Martin, Appl. Phys. Lett. 99, (2011) 083302 M. López-García, J.F. Galisteo-López, A. Blanco, J. Sánchez-Marcos, C. López and A. GarcíaMartín, Small 6, (2010) 1757 M. López-García, J.F. Galisteo-López, A. Blanco, C. López and A. García-Martín, Adv. Funct. Mater. 20, (2010) 4338

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Figures

Figure 1: a) Normal incidence reflectance (grey) and emission (black) for close-packed lattice of red dye dopped PS 520 nm polystyrene spheres on gold substrate. b) Evolution of emission with filling fraction variation. G1, G2 and G3 are the best defined modes shown as dips in reflectance in a)

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Nanobiocomposites with Graphene: Design and Perspectives

39 Kurt Geckeler1,2,3,* 1

Department of Nanobio Materials and Electronics, World-Class University (WCU), 2 School of Materials Science and Engineering, 3 Institute of Medical Systems Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea keg@gist.ac.kr

Figure 1: Schematic of a nanobio卢composite of DNA and grapheme

Nanobiocomposites have been found to be interesting materials for many applications and also the bottom-up approach for their preparation has received special attention in a series of studies [1-3]. Novel approaches for the synthesis of interesting nanobiocomposites can be designed and developed by using the concept of supramolecularity and other principles. The peculiarity of graphene in view of the dimensionality of the different carbon allotropes such as fullerenes and carb贸n nanotubes and their specific properties is highlighted. When employing nanosized building blocks in conjunction with other components such as biopolymers, these concepts can be translated into reality and new classes of nanobiocomposites can be fabricated.

These fundamentally novel concepts are presented both as synthetic methods and in the context of their applications with regard to graphene and its derivatives. The relevance of hydrophobicity and the dispersi贸n in different media are also covered in light of the different preparation methods as well as targeted applications. Several model systems with graphene and biopolymers as well as nanoparticles have been studied and examples of their interaction products based on different types of reactions and syntheses are given. The novel nanobiocomposites are expected to have an application potential in many areas such as the biomedical and electronic areas. Recent promising application examples are discussed and the perspectives of the graphene-based nanobiocomposites are analyzed. Acknowledgement This work was supported by the World Class University (WCU) program through a grant provided by the Ministry of Education, Science and Technology (MEST) of Korea (Project No. R31-10026). References [1] [2] [3]

K. E. Geckeler, H. Nishide (Eds.), Advanced Nanomaterials, Wiley-VCH Publishers, Weinheim, Germany, 2009. K. E. Geckeler, E. Rosenberg, (Eds.), Functional Nanomaterials, American Scientific Publ, Valencia, USA, 2006. K. E. Geckeler (Ed.), Advanced Macromolecular and Supramolecular Materials and Processes, Kluwer Academic/Plenum, New York, 2003.

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TNT 2011

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Tenerife - Spain

Catalytic Oxidation of Crude Glycerol using Au Catalyst Based on Carbonaceous Supports Sonia Gila*, Miriam Marchenaa, Carmen María Fernández a, Amaya Romerob, José Luís Valverdea a

Facultad de Ciencias Químicas /bEscuela Técnica Agrícola, Departamento de Ingeniería Química, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain. sonia.gil@uclm.es

Carbonaceous supports, typically activated carbon (AC) and graphite (G) are widely used in heterogeneous catalysis due to their specific properties, such as resistance to acid/basic media, possibility of controlling porosity and surface chemistry and easy recovery of the metal by burning off the support [1]. The discovery of novel carbon nanostructures, such as carbon nanofibers (CNF), nanotubes (CNT) and nanospheres (CNS), has led to increased activity in terms of catalytic applications. CNF are characterized by high aspect ratio bodies with enhanced mechanical strength and surface areas in the range 10-200 m2 g-1. They present a large amount of edges in the lattice and basal regions, providing increased metal-support interactions, and lower mass transfer constraints associated with their mesoporous character, in comparison with microporous activated carbons. CNS are typically isolated as a conglomeration of spherical bodies with low specific surface area (ca. 20 m2 g-1) but a high surface chemical activity provided by the unclosed graphitic layers, reactive open edges and “dangling bonds” which can enhance reactant adsorption. Therefore, it was considered of interest the study, as catalytic supports, in the selective oxidation of Figure 1: Influence of the nature of the carbonaceous commercial glycerol and crude glycerol, three carbon support: Glycerol conversion and glyceric acid materials with different morphology and crystallinity, selectivity as a function of time-on-stream. such as graphite (G), Ribbon type carbon nanofibers (CNF-R) and carbon nanospheres (CNS). The interest of this reaction is related to the increasing expansion of biodiesel production, 100 kg of glycerol, as a by-product, is produced per 1 tonne of biodiesel. Glycerol is a highly functionalized compound that could give rise to many compounds such as glyceric acid, hydroxypyruvic acid, glyceric acid, glycolic acid, mesoxalic acid, oxalic acid, tartronic acid, etc. [2]. However, glycerol resulting as a by-product of transesterification process typically contains a mixture of methanol, water, inorganic salts (catalyst residue), free fatty acids, unreacted mono-, di- and triglycerides, methyl esters, and a variety of other organic materials in varying qualities, depending on the biodiesel process [3]. As consequence, crude glycerol, with an estimated 50% purity, has few direct uses and is considered as a low value product. For this reason, the present study was focused in the revalorization of crude glycerol to obtain products of high value. Thus, different Au catalyst based on carbonaceous supports has been tested in the selective oxidation of glycerol of different purity: crude glycerol, crude glycerol purified by evaporation using a vacuum flash process, crude glycerol neutralized with hydrochloric acid and, with comparative ends, commercial glycerol.

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CNF-R supports were prepared by the catalytic decomposition of ethylene over Ni/SiO2 at 1023 K, CNS were synthesized via the pyrolysis of benzene and G support was commercially acquired [4, 5]. The metal function (Au) was supported by the sol-gold method using THPC as oxidizing agent (-SGT). All the supports and catalysts were characterized by the following techniques: N2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature programmed oxidation (TPO), temperature programmed desorption (TPD) and Figure 2: Influence of the purification treatment of temperature programmed reduction (TPR). Catalytic crude glycerol: Glycerol conversion and glyceric activity measurements were carried out with oxygen acid selectivity as a function of time-on-stream. under pressure to 5 bar, 333 K, 300 ml of a 0.3 M glycerol solution, glycerol/Au = 3500 mol/mol, 1000 rpm and NaOH/glycerol = 2 mol/mol. The physicochemical properties of the supports have been described in detail elsewhere [5, 6]. Table 1 and Figure 1 show how, the nature of support and Au particle size influences on catalytic results. It could be observed as, these two parameters played an important role in the deposition of Au particles and thus, in its catalysis. Both conversion and selectivity increased in decreasing the Au particle size and increasing the metal dispersion. Respect to the nature of the support, it was observed as crystalline materials, such as G, promoted a better anchoring of small and well dispersed Au particles (which facilitates the abstraction of protons of glycerol, increasing conversion) compared to partially crystalline supports such as CNF. By its part, Au catalysts based on CNS, presented a very good dispersion of small Au particles, which favored its catalytic activity. In addition, in all cases, catalytic activity using commercial glycerol was superior respect to the crude glycerol. Nevertheless, after purification of the crude glycerol by neutralization, the catalytic activity was similar to that obtained using the commercial one, suggesting that this could be an interesting low cost alternative to revalorization of crude glycerol to obtain products of high added value. Catalysts

തതത ݀௦ (nm)

BET surface area (m2g-1)

Total pore volume (cm3g-1)

d002 (nm)

Lc (nm)

Time (h)

SGLYAa (%)

SMOXALAa (%)

SGLYCAa (%)

SHPYAa (%)

STARACa (%)

SOXALAa (%)

Au/G

7.7

9.83

0.019

0.338

321.8

62.9

0.0

25.4

3.2

4.1

4.4

COMMERCIAL

Au/CNF

13.2

104

0.029

0.342

8.75

44.1

3.3

37.9

4.3

7.2

3.2

GLYCEROL

Au/CNS

4.2

2.54

0.011

0.347

30.53

68.0

3.7

24.2

1.4

1.9

0.9

Au/G

7.7

9.83

0.019

0.338

321.8

22.2

4.7

66.2

4.3

2.1

0.5

CRUDE

Au/CNF

13.2

104

0.029

0.342

8.75

14.5

11.1

58.4

11.4

3.2

1.5

GLYCEROL

Au/CNS

4.2

2.54

0.011

0.347

30.53

26.4

9.2

49.0

6.4

7.7

1.3

Table 1: Physicochemical properties of the Au catalysts and influence of support and Au particles size on the selectivity to several reaction products. a Selectivity to glyceric acid (GLYA), glycolic acid (GLYCA), tartronic acid (TARAC), oxalic acid (OXALA), mesooxalic acid (MOXALA) and hydroxypyruvic acid (HPYA), respectively, at 35% of glycerol conversion.

References [1] [2] [3] [4] [5] [6]

P. Serp, M. Corrias and P. Kalck, Appl. Catal. A: General 253 (2003) 337. S. Demirel-Gülen, M. Lucas, P. Claus, Catal. Today, 102, 166 (2005). C.-H. Zhou, J.N. Beltramini, Y.-X. Fana, G.Q.Lu, Chem. Soc. Rev., 37 (2008) 527. V. Jiménez, A. Nieto-Márquez, J.A. Díaz, R. Romero, P. Sánchez, J.L. Valverde, A. Romero, Ind. Eng. Chem. Res. 48 (2009) 8407. A. Nieto-Marquez, R. Romero, A. Romero, J.L. Valverde, J. Mater. Chem., 21 (2011) 1664. S. Gil, L. Muñoz, L. Sánchez-Silva, A. Romero, J.L. Valverde, Chem. Eng. J., 172 (2011) 418.

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High-Resolution Molecular Imaging with STM and AFM using Functionalized Tips

43 Leo Gross, Fabian Mohn, Nikolaj Moll and Gerhard Meyer IBM Research - Zurich The contrast mechanisms of noncontact atomic force microscopy (NC-AFM) and scanning tunnelling microscopy (STM) using functionalized tips are discussed for the case of single organic molecules, such as pentacene, naphthalocyanine (see Fig. 1), and PTCDA. Using atomic manipulation, the tip of an AFM or STM can be functionalized in a controlled manner. As a result the contrast can be increased, and even more important the interpretation of images benefits from the knowledge of the chemical composition of the tip apex [1]. Using NC-AFM with CO terminated tips, atomic resolution on molecules has been demonstrated and the contrast mechanism was assigned to the Pauli repulsion [2] (see Fig.1c). On the other hand, by using STM and by decoupling the molecules from the metallic substrate by an ultrathin insulating film, the molecular frontier orbitals, i.e. the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO), were mapped [3] (see Fig1b). Moreover, using a CO terminated tip for orbital imaging with the STM, the images correspond to the gradient of the molecular orbitals due to the p-wave character of the tip states [4] (see Fig. 1d). Thus, combining AFM and STM with different tip functionalization, complementary information is obtained. We made use of this combination of methods for the investigation of a molecular switch based on the reversible bond formation in an atom-molecule complex [5]. References [1] [2] [3] [4] [5]

L. Gross, Nature Chem. 3, 273 (2011) L. Gross et al. Science 325, 1110 (2009) J. Repp et al. Phys. Rev. Lett. 94, 026803 (2005) L. Gross et al. Phys. Rev. Lett. 107, 086101 (2011) F. Mohn et al. Phys. Rev. Lett. 105, 266102 (2010)

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TNT 2011

November 21-25, 2011

Tenerife - Spain

Domain-structure-induced giant magneto-impedance

45 Uwe Hartmann Institute of Experimental Physics, Saarland University, P.O.Box 151150, D-66041 Saarbr端cken, Germay Already in 1935 it was discovered that a ferromagnetic wire changes its impedance as a function of an externally applied magnetic field[1]. Respective resistances changes have, of course, been reported much earlier[2]. The giant magneto-impedance effect (GMI), which is now widely studied, was first observed on Co-based amorphous wires in 1994[3]. The effect involves considerable changes of the complex electrical impedance of a ferromagnetic sample as a function of externally applied magnetic fields. The relative impedance change can typically amount to a few hundred percent. We have recently discovered a variant of the GMI effect on iron whiskers with a very simple domain structure which is caused by periodic changes of the whole domain structure[4]. These changes are the result of circular magnetization reversals generated by the Oerstedt field of the transport current and are thus strongly frequency- and amplitude-dependent. A typical variation of the relative impedance change as a function of externally applied field is shown in Fig. 1. AC transport measurements, MOKE investigations and micromagnetic calculations allowed us to conclude that domain configurations, as shown in Fig. 2, are present. Their interplay with the electromagnetic skin effect causes the GMI effect and makes it relevant already at relatively low frequencies. The contribution discusses the results in detail, involves data obtained at room temperature as well as at low temperatures and focuses on the question to which extend the effect can be utilized involving nanoscale structures of technological importance. References [1] [2] [3] [4]

E.P. Harrison, G.L. Turney and H. Rowe, Nature, 135 (1935). W. Thompson, Proc. Roy. Soc. 8, 546 (1856-57). L. V. Panina and K. Mohri, Appl. Phys. Lett. 65, 1189 (1994). M. Langosch, H. Gao and U. Hartmann, J. Phys. D: Appl. Phys. (submitted).

Figures

Figure 1: Change of the relative impedance of iron whiskers as a function of an external magnetic field, applied in longitudinal direction.

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Figure 2: Current-induced domain configuration at low (upper part) and high (lower part) frequencies.

November 21-25, 2011

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TNT 2011

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Atom/ion movement controlled three-terminal atomic switch, ‘Atom Transistor’

47 Tsuyoshi Hasegawa1,2, Yaomi Itoh1,2, Tohru Tsuruoka1,2, and Masakazu Aono1 1 MANA, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, 305-0044 Japan Japan Science and Technology Agency, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan

HASEGAWATsuyoshi@nims.go.jp Atomic switch is a nanoionic-device that controls the diffusion of metal ions/atoms and their reduction/oxidation processes in the switching operation to form/annihilate a conductive path [1-3]. Since metal atoms can provide a highly conductive channel even if their cluster size is in the nanometer scale, atomic switches may enable downscaling to smaller than the 11 nm technology node, which is a great challenge for semiconductor devices. Atomic switches also possess novel characteristics, such as high on/off ratios, very low power consumption and non-volatility. Although two-terminal devices work as logic devices such as the crossbar circuit, three-terminal devices, in which signal line and control line are separated, are advantageous for the logic applications.

Figure 1: Operating mechanism of the Atom Transistor.

We recently developed an atom movement controlled three-terminal device: ‘Atom Transistor’ [4]. It operates by bringing metal cations from the gate electrode, which form a conductive channel between the source and drain electrodes. Schematic illustration of the operation is shown in Figure 1. It possess novel characteristics, such as the dual functionality of selective volatile and nonvolatile operations, very small power consumption (pW), and a high on/off ratio (106 (volatile operation) to 108 (nonvolatile operation)), in addition to being compatible with CMOS processes, which enables their use in the development of computing systems that fully utilize highly-integrated CMOS technology. It is also expected to achieve the nonvolatile logic operations.

Acknowledgement The development has been achieved in collaboration with groups of Profs, S. Yamaguchi, S. Watanabe and T. Hiramoto of Univ. of Tokyo, and Prof. T. Ogawa of Osaka Univ. I also thank coworkers in NIMS. References [1] [2] [3] [4]

K. Terabe et al., Nature, Authors, Journal, 433 (2005) 47. M. Aono and T. Hasegawa, Proc. IEEE, 98 (2010) 2228. T. Hasegawa et al., Adv. Mater., DOI: 10.1002/adma.201102597. T. Hasegawa et al., Appl. Phys. Express, 4 (2011) 15204.

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TNT 2011

November 21-25, 2011

Tenerife - Spain

Time of Flight Mass Spectrometry for analysis of nano- and plasma modified materials Josef Havel 1,2,3, Pavel Sťahel, Mirko Černák 2,3 1

Department of Chemistry, Faculty of Science, Masaryk University, A14/107, Kamenice 753/5, Bohunice, 625 00 Brno, Czech Republic 2 Department of Physical Electronics, Masaryk University, Kotlářská 2, 611 37 Brno 3 R&D Center for Low-Cost Plasma and Nanotechnology Surface Modifications, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic havel@chemi.muni.cz More than 100 years passed since the construction of the first mass spectrometer (Thomson in 1906) and now this instrumentation belongs to the most important analytical techniques in all branches of chemistry, science and technology. The discovery of Matrix Assisted Laser Desorption Ionization (MALDI) with Time Of Flight (TOF) detector – MALDI TOF MS enabled to ionize biomolecules without theirs fragmentation and importance of such invention was evaluated by giving Nobel Prize (1/4) to Koichi Tanaka (in 2002). MALDI TOF MS is now the leading analytical instrumentation for studying bio-molecules, pharmaceuticals products, peptides, proteins, polymers, and any kind of molecules with masses even exceeding 1 000 000 Daltons. Applications include first of all genomics and proteomics.

Instrumentation of Time Of Flight Mass Spectrometry (TOF MS) with ionization either using matrices (MALDI) or applying just Laser Desorption and Ionization (LDI) represents suitable instrumental technique also for MS analysis of nanoFigure 1: Scheme of TOF MS (up) and experimental materials. Still it is perhaps not realized fully that TOF MS can set up for nano-materials analysis. TOF MS spectrum of nano-diamonds (down). also be applied with advantage to analyze inorganic compounds, adsorbed organic and/or inorganic compounds on various surfaces, to study chemical structure of the inorganic polymers, plasma modified surfaces of inorganic, organic and hyphenated materials and also of nano-materials and nano-layers. In this work basic principles of TOF MS will be elucidated and the possibilities of TOF MS illustrated by extensive applications and examples of bulk, nano-materials and plasma modified surfaces, while the advantages but also the limitations and future trends will be mentioned and discussed. As for the instrumentation is concern, most often a nitrogen UV laser (337 nm) is applied to generate ions and under the use of a suitable matrix like e.g. alpha-cyano-4-hydroxy cinnamic acid (CHC), or 2,5-dihydroxy benzoic acid, etc. even large molecular weight compounds like proteins can be ionized without any strong fragmentation. The mechanism of ionization remains still not completely resolved but it is sure it may involve absorption of UV light pulse by the matrix with consecutive transfer of energy to the analyzed molecule - which then undergoes ionization in plasma phase as a result of the relatively large amount of energy absorbed. In order to move resulting ions down the flight tube in the mass spectrometer the ions are accelerated in an electric field (up to 25 kV). The analysis can be done either in positive or negative ion modes and in linear or reflectron arrangements. Simplified scheme of TOF MS and experimental set up is given in Figure 1. Various applications of TOF MS to analyze the surfaces of organic or inorganic materials, bulk, nano-materials, clusters etc. will be demonstrated and discussed.

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•

• • •

•

TOF MS can be used, for example to detect and/or analyze adsorbed molecules on various surfaces. To clean e.g. chip surface is not an easy task. Chemical methods of cleaning might be substituted by plasma treatment. Plasma treated surfaces are finding extensive applications in technology, industry and medicine etc, as we have reviewed recently [1]. Chemical changes on various surfaces like glass [2], silicon [3], mica and also polymers and natural materials due to application of diffuse coplanar barrier discharge has been studied recently. The surface is cleaned and adsorbed organic compounds removed but also activated Deposition of e.g. gold nano-particles on such cleaned surface is then facilitated. Advantages in using TOF MS for analysis of nanomaterials have been demonstrated in literature and also in several our papers. Most of the nano-materials especially carbon nano tubes, but also nano-silver [4] are toxic. The exception seems to be nano-gold [5] which is now extensively used in nano-medicine. Formation of nano-gold clusters in plasma via MS analysis was studied in [6]. Nano-gold is now extensively studied for photo-thermal therapy of cancer. Another class of nano-materials finding applications in medicine are nano-diamonds. We have recently analyzed and characterized them [7]; some other details of TOF MS analysis will be given. Extensive applications are those concerning the determination of structure of chalcogenide glasses as demonstrated in [7-10] and will be discussed. Instrumentation of TOF MS can also be used as a synthesizer. Laser ablation synthesis from various precursors has been shown in several papers, i.e. clusters were generated by laser ablation from AgSbS2 nano-material or from pulsed laser deposited layer of this material as it was demonstrated in [12]. The synthesis of new phosphorus-nitride clusters from α-P3N5 [11], or e.g. laser ablation synthesis of selenium tetroxide, SeO4, was shown in [13]. Several other examples (non published data) will be also shown and discussed.

Concluding, TOF MS instrumentation can be used to analyze adsorbed chemical compounds on various surfaces, to study chemical changes of polymers or inorganic materials due to modification by plasma, to perform analysis of nano-layers, glasses, modified carbon nanotubes, nano-diamonds and/or also to perform structural analysis of nano-layers or bulk materials. Perspectives and future trends of TOF MS applications in nano-science and nano-technology are elucidated while problems and limitations are discussed, as well. Acknowledgement Support from Ministry of Education, Youth and Sports of the Czech Republic (Projects MSM, 0021622411, 0021627501, and CZ.1.05/2.1.00/03.0086), and Czech Science Foundation (Projects No. 104/08/0229, 202/07/1669) are greatly acknowledged. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]

S. Cheruthazhekatt, M. Černák, P. Slavíček and J. Havel: J. Applied Biomed. 8 (2010), 55. L. Rusnáková N. R. Panyala, V. Štěpánová, P. Slavíček, M. Černák, J. Havel: to be published. A. Pamreddy, D.Skácelová, M. Haničinec, P. Sťahel, M. Černák and J. Havel: to be published. N. R. Panyala, E. M. Peña-Méndez, J. Havel: J. Appl. Biomed. 6 (2008), 117. N. R. Panyala, E. M. Peña-Méndez and J. Havel: J. Appl. Biomed. 7 (200), 75. E. M. Peña-Méndez, J. R. Hernández- Fernaud, N. R. Panyala, J. Houška and J. Havel: Chem. Listy, 102 (2008), 1394. J. Houška, N. R. Panyala, E. M. Peña-Méndez, J. Havel: Rapid Commun. Mass Spectrom. 23 (2009),1125. S. D. Pangavhane, P. Němec, T. Wágner, J. Janča, J. Havel: Rapid Commun. Mass Spectrom. 24 (2010), 2000. S. D. Pangavhane, J. Houška, T. Wágner, M. Pavlišta, J. Janča, J. Havel: Rapid Commun. Mass Spectrom. 24 (2010), 95. G. Ramírez-Galicia, E. M. Peña-Méndez, S. D. Pangavhane, M. Alberti, J. Havel: Polyhedron 29 (2010), 1567. S. D. Pangavhane, L. Hebedová, M. Alberti, J. Havel: Rapid Commun. Mass Spectrom. 25 (2011), 917. J. Houška, E. M. Peña-Méndez, J. Kolář, M. Frumar, T. Wágner, J. Havel: Rapid Commun. Mass Spectrom. 23 (2009), 1715. M. Alberti, Z. Špalt, E.M. Peña-Méndez, G. Ramirez-Galicia, and J. Havel, Rapid Commun. Mass Spectrom. 19 (2005), 3405. J. Houska, M. Alberti, J. Havel: Rapid Commun. Mass Spectrom.. 22 (2008), 417.

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Infrared and Terahertz Nanoscopy

51 Rainer Hillenbrand CIC nanoGUNE, Donostia - San Sebastian, Spain r.hillenbrand@nanogune.eu During the last years, near-field microscopy based on elastic light scattering from atomic force microscope tips (scattering-type scanning near-field optical microscopy, s-SNOM) has become a powerful tool for nanoimaging of local dielectric material properties and optical near fields of photonic nanostructures [1]. Interferometric detection yields nanoscale resolved optical amplitude and phase images, simultaneously to topography. Employing IR and THz illumination of about λ = 10 μm and 118 μm wavelength, a wavelength-independent resolution better than 40 nm has been already demonstrated, corresponding to λ/250 and λ/3000, respectively [2]. Using metal-coated tips, the strong field enhancement at the tip apex probes the local dielectric properties of a sample. We demonstrate that dielectric mapping enables the simultaneous recognition of materials and free-carrier concentration in semiconductor nanodevices [2] and nanowires [3]. Quantitative free-carrier mapping we achieve by near-field plasmon-polariton spectroscopy, which can be also applied to study strain-induced changes of carrier concentration and mobility [3, 4]. Recently, we succeeded in performing s-SNOM with the thermal radiation from a blackbody, which offers the possibility of mapping broadband infrared spectra with a spatial resolution better than 100 nm [5]. We also demonstrate that s-SNOM can be used for imaging the vectorial near-field distribution of photonic nanostructures. In this application, a dielectric tip scatters the near fields at the sample surface. The amplitude and phase-resolved measurement of different near-field components allows for mapping of the polarization state in nanoscale antenna gaps [6], of near-field modes in loaded infrared gap antennas [7] and of mid-infrared energy transport and compression in nanoscale transmission lines (see figure) [8].

References [1] [2] [3] [4] [5] [6] [7] [8]

F. Keilmann, R. Hillenbrand, Phil. Trans. R. Soc. Lond. A 362, 787 (2004) A. J. Huber, F. Keilmann, J. Wittborn, J. Aizpurua, R. Hillenbrand, Nano Lett. 8, 3766 (2008) J. M. Stiegler, et al., Nano Lett. 10, 1387 (2010) J. A. Huber, A. Ziegler, T. Koeck, R. Hillenbrand, Nature Nanotech. 4, 157, (2009) F. Huth, M. Schnell, J.Wittborn, N. Ocelic, R. Hillenbrand, Nature Mater. 10, 352 (2011) M. Schnell, A. Garcia-Etxarri, J. Alkorta, J. Aizpurua, R. Hillenbrand, Nano Lett. 10, 3524 (2010) M. Schnell, A. Garcia-Etxarri, A. J. Huber, K. B. Crozier, J. Aizpurua, R. Hillenbrand, Nature Photon. 3, 287 (2009) M. Schnell, P. Alonso-Gonzalez, L. Arzubiaga, F. Casanova, L. E. Hueso, A. Chuvilin, R. Hillenbrand, Nature Photon. 5, 283 (2011)

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52 Figures

Figure 1: Infrared nanofocusing with tapered transmission lines. Left: Concept. Right: s-SNOM image of the tapered transmission line structure, taken at 9.3 Îźm wavelength. It shows the infrared field intensity (vertical axis) along the transmission line, revealing the nanofocus at the taper apex.

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Measurement of tip-sample interaction forces under infrared irradiation toward high-spatial-resolution infrared spectroscopy using FM-AFM (2) Yoshihiro Hosokawa1, Hans-Georg von Ribbeck2, Rainer Jacob2, Marc Tabias Wenzel2, Lukas Eng2, Kei Kobayashi1 Kazumi Matsushige1 and Hirofumi Yamada1

1 Department of Electronic Science and Engineering, Kyoto University Institute for Applied Photophysics, Technical University of Dresden, Germany

hosokawa@piezo.kuee.kyoto-u.ac.jp Infrared (IR) spectroscopy is a superior, analytical technique which is capable of identifying functional groups having characteristic vibration frequencies. However, the spatial resolution in the conventional IR spectroscopy is on the order of micrometers because of the diffraction limit. Recently, several researchers demonstrated high-spatial-resolution IR spectroscopy by detecting thermal expansions on a sample surface using atomic force microscopy (AFM) under IR irradiation[1,2]. They succeeded in detecting a cantilever deflection induced by the thermal expansion by the contact-mode AFM. However the spatial resolution was still limited around 100 nm because of the contact radius of the cantilever tip. Frequency-modulation AFM (FM-AFM) is capable of measuring tip-sample interaction forces with a very high sensitivity. In this technique, we modulated the IR power and detected the AFM signal using a lock-in amplifier (Fig.1). Recently, we succeeded in detecting the modulated frequency shift of the cantilever resonance frequency when the cantilever was brought in close proximity of a polymer film surface irradiated with an IR beam using a free electron laser (Forschungszentrum Dresden-Rossendorf, Germany)[3]. In this experiment a polydimethylsiloxane (PDMS) film spin-coated on a Si surface was used as a sample. The IR beam was modulated using an optical chopper at 530 Hz. The tip, made of Si, was scanned on the same scan line while we changed the wavelength of the IR beam from 6.79 um to 8.22 um for each scan. Figure 2(a) shows an image consisting of one-dimensional topographic data (X) for different IR wavelengths (Y) and Fig. 2(b) shows the wavelength dependence of the modulation components in the frequency shift and energy dissipation signals obtained on the PDMS area. Both signal intensities were normalized to the corresponding values on the Si area. The data were acquired on the dashed lines in Fig. 2(a). We found that some peaks in Fig. 2(b) corresponded to the absorption peaks in a infrared absorption spectrum of the PDMS film, obtained by a conventional FT-IR measurement. For more precise analysis of the tip-sample interaction forces of FM-AFM on polymer thin films under IR irradiation, a quantum cascade laser (QCL) was used. In this experiment a spin-coated PDMS film deposited on a highly-oriented pyrolytic graphite (HOPG) surface was used, as shown in Fig. 3(a). While the distance between the AFM tip and the sample surface was regulated utilizing the second resonance frequency (420 kHz) of the cantilever, the sample surface was irradiated with an IR beam from the QCL (1050 cm-1) whose intensity was modulated at a frequency close to the first resonance frequency (67 kHz). Figure 3 (b) shows an FM-AFM topographic image, and Figs. 3 (c) and (d) show the magnitude of the cantilever oscillation induced by the IR irradiation at 69 kHz and 65 kHz, respectively. In both Figs. 3(c) and 3(d) the magnitude of the cantilever oscillation on PDMS is clearly different from that on HOPG. The result also shows a remarkable change of the contrast between the PDMS and the HOPG depending on the modulation frequency.

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Reference

[1] [2] [3]

F. J. Boerio and M. J. Starr, Journal of Adhesion (2008) 84 874. A. Dazzi, R. Prazeres, F. Glotin and J. M. Ortega, Optics Letters (2005) 30 18. Y. Hosokawa et al. 18th International Colloquium on Scanning Probe Microscopy, (2010)

Figures

Figure 1: Schematic of novel infrared spectroscopy using FM-AFM. A tip-sample interaction change caused by a modulated IR beam is detected using lock-in amplifier.

Figure 2: (a) FM-AFM image consisting of one-dimensional topographic data (X) for different IR wavelengths (Y), obtained on a PDMS film on a Si substrate. (b) Normalized intensities of the modulation components in the frequency shift (â&#x2014;?) and energy dissipation signals (â&#x2014;&#x2039;) obtained on the PDMS area, which were normalized to the corresponding values on the Si area. (C) Infrared absorption spectrum of the PDMS film.

Figure 3: (a) Illustration of the sample (PDMS film on HOPG). (b) Topographic image of PDMS film on HOPG. (c) and (d) show images of the cantilever oscillation magnitude induced by irradiation of IR laser beam modulated at 69 kHz and 65 kHz, respectively.

TNT 2011

November 21-25, 2011

Tenerife - Spain

Sakurai-Sugiura algorithm based eigenvalue solver for Siesta

55 Georg Huhs Barcelona Supercomputing Center, c/ Gran Capita 2-4, 08034 Barcelona, Spain. georg.huhs@bsc.es In ab initio calculations based on density functional theory very often the most time consuming step is the solution of the generalized eigenvalue problem appearing in the self consistent loop. This applies also for Siesta, a DFT code currently using ScaLAPACK for this purpose. This standard-package has two disadvantages. First, due to the atomic orbital basis set of Siesta, the matrices to deal with are sparse, whereas ScaLAPACK is meant for dense systems. Second, Siesta is meant for using thousands of processors for thousands of atoms, thus an even better scaling method is needed. The Sakurai-Sugiura algorithm has the capability of solving this issue. This talk shows how: • • •

this method shifts the problem to solving linear systems, which is much easier to deal with it offers three levels of parallelization, giving the possibility of using many processing units efficiently also the fact of being applied inside of an iterative loop can be used to accelerate the computation

The Barcelona Supercomputing Center is currently working on implementations for both, CPU and GPU systems, so the most recent performance results for several conﬁgurations can be shown. References [1]

[2]

[3] [4]

J. M. Soler, E. Artacho, J. D. Gale, A. García, J. Junquera, P. Ordejón and D. Sánchez-Portal, J. Phys.: Condens. Matter 14, The Siesta method for ab initio order-N materials simulation (2002) 2745-2779. E. Artacho, E. Anglada, O. Dieguez, J. D. Gale, A. García, J. Junquera, R. M. Martin, P. Ordejón, J. M. Pruneda, D. Sánchez-Portal and J. M. Soler, J. Phys.: Condens. Matter 20, The Siesta method; developments and applicability (2008) T. Sakurai, H. Sugiura, Technical Report ISE-TR-02-189 University of Tsukuba, A projection method for generalized eigenvalue problems (2002) I. Ikegami, T. Sakurai, U. Nagashima, Technical Report S-TR-08-13 University of Tsukuba, A filter diagonalization for generalized eigenvalue problems based on the Sakurai-Sugiura projection method (2008)

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November 21-25, 2011

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TNT 2011

November 21-25, 2011

Tenerife - Spain

Density functional calculation for various adatom adsorptions on graphene for using graphene as substrate of nanomaterial Akira Ishiia,b, Kengo Nakadaa,b a

Department of Applied Mathematics and Physics, Tottori University Koyama, Tottori 680-8552, Japan b JST-CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan ishii@damp.tottori-u.ac.jp

The graphene itself is very interesting material to be investigated both experimentally and theoretically. Nowadays, excellent experiments for graphene sheets become possible. However, the graphene is very interesting also for substrates of nanostructure because of its two dimensionality. In order to promote such investigations, the adsorption of atoms and molecules on graphene should be studied, but such studies have not been done so much. In recent theoretical study[1,2,3,4], the adsorption sites and adsorption energies for some atomic species have been reported. The aim of this investigation is understanding of the general mechanism of the adatom adsorption on a graphene sheet. In this work, we investigate computationally adsorption energies, adsorption sites and migration barrier energies on graphene sheet for a lot of atomic species including transition metals, noble metals, nitrogen and oxygen, from atomic number 1 to 83, using the DFT calculation. We used VASP[5,6,7,8] which was first-principle calculation code of the high precision using the PAW method. The calculations are done for adatom at three site having symmetry, H(hexagonal),B (bridge) and T (on-top) on 3 x 3 super cell. The spin-polarization is included in the calculation. The both magnetic and non-magnetic calculations are done. We discuss stability of the adatom in the graphene by analysis from the electronic structure. The calculated results show that adsorption at the H-site mainly for simple and transition metal elements. The non-metallic element showed the tendency to be adsorbed at the B-site. As shown in fig.1, some atomic species have chemisorption adsorption. Many metallic adatoms show ferromagnetic behavior at least for single adsorption on graphene. As shown in figure 2 for Mn on graphene, we found in our DFT calculation that some transition metal atoms adsorb in vertical alignment with spin polarization. Such structure can be applied to some nano-scale magnetic devices. Moreover, magnetic behavior of adatoms on graphene is also reported along the atomic elements table. In figure 3, we show the calculation for nitrogen as an example of non-metal elements. The result of this work will be helpful for the choice of material for electrode on graphene or growth of graphene on substrates. This work is supported by JST-CREST project.

References [1] [2] [3]

A. Ishii, M. Yamamoto, H. Asano and K. Fujiwara, Journal of Physics: Conference Series 100 (2008) 052087. A. Ishii, T. Tatani, H. Asano and K. Nakada, phys. stat. sol. (c) 7 347-350 (2010). T.Nakada and A.Ishii, solid state commun. 151 (2011) 13.

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[4]

58 [5] [6] [7] [8]

Kengo Nakada and Akira Ishii (2011). DFT Calculation for Adatom Adsorption on Graphene, Graphene Simulation, Jian Ru Gong (Ed.), ISBN: 978-953-307-556-3, InTech, Available from: http://www.intechopen.com/articles/show/title/dft-calculation-for-adatom-adsorptionongraphene . G. Kresse and J. Hafner, Phys. Rev. B 47, RC558 (1993). G. Kresse, Thesis, Technische Universitat Wien 1993. G. Kresse and J. Furthmuller, Comput. Mat. Sci. 6, 15-50 (1996). G. Kresse and J. Furthmuller, Phys. Rev. B 54, 11169 (1996)

Figures

Figure 1: Calculated wave function image of a typical orbital for the adsorption of chromium adatom on graphene using non-magnetic DFT calculation. The picture shows us the strong hybridization of chromium orbital and carbon orbitals of graphene.

Figure 2: The adsorption structure of transition metal atoms on gprahene with vertical alignment. The figure is the example of spin density map for two Mn atoms on graphene obtained by using the density functional calculation. The calculation shows magnetic polarization for the two Mn atoms.

Figure 3: The calculated local density of states for nitrogen adatom at the most stable site on graphene. The result shows us the magnetic polarization of nitrogen on graphite.

TNT 2011

November 21-25, 2011

Tenerife - Spain

Proximity induced superconductivity in DNAs

59 A. Kasumov1, A.D. Chepelianskii1, D. Klinov2, S. GuĂŠron1, O. Pietrement3, S. Lyonnais4, H. Bouchiat1 1 Univ. Paris-Sud, CNRS, UMR 8502, F-91405, Orsay, France. Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow 117871, Russia. 3 UMR 8126 CNRS-IGR-UPS, Inst Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France. 4 Museum National d'Histoire Naturelle, CNRS, UMR7196, 43 rue Cuvier, 75005 Paris, France. 2

kasumov@lps.u-psud.fr In this report we reconcile previous findings [1-3] by showing that conduction over distances greater than hundreds of nanometers can occur if the DNA molecules are attached to a disconnected array of nanoparticles (typically 10 to 20 nm apart) that locally dopes the molecules, enhancing conduction. In addition in our case the nanoparticles are superconducting, which induces superconducting correlations in DNA at low temperatures. In the following we present low temperature transport measurements of DNA molecules deposited through slits decorated with gallium nanoparticles (Fig.1). The samples investigated have resistances ranging from 5 to 20 kOhm at room temperature, with roughly 10 to 30 connected molecules, as deduced from the density of molecules on the substrate far from the slit. The samples were electronically and mechanically connected by gold plated spring contacts on the gold pads on the Pt/C film, and mounted in a dilution refrigerator operating down to 50 mK. The resistance was measured via lines with room temperature low pass filters. Measurements were performed in a current biased configuration using an ac current source of 1 nA operating at 27 Hz and a Lock-in detector with a low noise voltage pre-amplifier. Whereas the resistance was nearly independent of temperature between room temperature and 4 K, it dropped as T decreased, with a broad transition to a value of the order of 4 kOhm (which corresponds to the resistance of the normal Pt/C electrodes in series with the DNA molecules), see Fig. 1. This transition to partial proximity-induced superconductivity is shifted to lower temperatures in a magnetic field. It is the broadest for the most resistive sample, and exhibits the smallest magnetic field dependence. Another superconducting-like feature is the non linear IV curves at low temperature, see Fig. 2: The dc current-dependent differential resistance is lowest at small dc current and increases with increasing dc current. The increase is non monotonous, presenting several peaks up to a current of the order of 1 ÎźA, a sort of critical current, above which the resistance is constant and independent of dc current. The many peaks in the differential resistance curves are typical of non homogeneous superconductivity. For instance the differential resistance jumps seen in narrow superconducting wires (diameter smaller than coherence length) are associated with the weak spots of the wire. Since neither the Pt/C electrodes nor the DNA molecules are superconducting (as shown in previous experiments), these results suggest that the gallium nanoparticles, which are superconducting, induce superconductivity through the DNA molecules. The superconducting transition temperature of pure gallium is Tc=1 K but it is reasonable to expect that the gallium nanoparticles, because of their small size and their probable large carbon content, have a higher Tc [4]. It is interesting to note that the low intrinsic carrier density in the DNA molecules may prevent the inverse proximity effect, i.e. the destruction of the superconductivity of the gallium nanoparticles. Those same nanoparticles could not induce any proximity effect in metallic wires because of the high density of carriers in metals. This possibility of inducing long range superconductivity with superconducting nanoparticles was

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investigated recently in the context of graphene [5]. In the present case, it is also possible that the gallium nanoparticles could contribute to carrier doping of the DNA molecules in the normal state. These results invite to a systematic investigation of the possible carrier doping of DNA by metallic nanoparticles. References [1] [2] [3] [4] [5] [6]

A. Yu. Kasumov, M. Kociak, S. Guéron, B. Reulet, V. T. Volkov, D. V. Klinov and H. Bouchiat, Science 291 (2001) 280. A. Yu. Kasumov, D. V. Klinov, P.-E. Roche, S. Guéron, H. Bouchiat, App.Phys.Lett. 84 (2004) 1007. A.Yu. Kasumov, S. Nakamae, M. Cazayous, T. Kawasaki, Y. Okahata, Research Letters in Nanotechnology (2009) Article ID 540257. O. N. Bakharev et al Phys.Rev.Lett. 96 (2006) 117002. M.V. Feigel'man, M.A. Skvortsov and K.S. Tikhonov, Solid State Comun. 1101 (2009).

Figures

← Figure 1: a) Atomic force microscopy image of one of the sample where low temperature transport was investigated, taken using an ultra sharp AFM tip and showing the presence of a DNA molecule across the slit. The slit is nearly invisible due to the scanning direction chosen to be parallel to the slit in order to optimize the DNA visualization. b) Electron microscopy image of the same sample. Gallium nanoparticles are clearly visible in the etched slit region. c),d) Low temperature dependence at several magnetic fields (going from 0 to 5T) of the resistance for 2 different samples where Ga nanoparticles are present inside the slit as described in the inset of the top panel. Inset of d): magnetic field dependence of the critical temperature Tc(H) deduced from the inflexion points of the R(T) curves.

↑Figure 2: The black curve represents the differential resistance dV/di as a function of DC current through the 10 kOhm sample at 100 mK. The color inset in the background shows the evolution of the differential resistance encoded as a color scale with yellow/violet representing maximal/minimal differential resistance. The x axis represents the DC-current as in the main figure, and the y axis indicates the magnetic field ranging from 0 to 5 Tesla.

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Particle configurations and gelation in capillary suspensions

61 Erin Koos, Jens Dittmann, and Norbert Willenbacher Karlsruhe Institute of Technology, Gotthard-Franz-Straße 3, 76131 Kalrsruhe, Germany erin.koos@kit.edul When a small amount (less than 1%) of a second immiscible liquid is added to the continuous phase of a suspension, the rheological properties of the mixture are dramatically altered from a fluid-like to a gellike state (Figure 1). The yield stress and viscosity increase by several orders of magnitude as the volume of the second fluid increases (Figure 2). This transition is attributed to the capillary forces of the two fluids on the solid particles, and in an analogy to wet granular materials, two distinct states are defined: the "pendular state" where the secondary fluid preferentially wets the particles; and the "capillary state" where the secondary fluid wets the particles less well than the primary fluid. We find that both states are associated with a transition in the suspension from a fluid-like to gel-like state [1]. Capillary suspensions, suspensions with the addition of a small amount of a second immiscible liquid, are a new class of materials that can be used to create tunable fluids, stabilize mixtures which would otherwise sediment, and to create new materials such as low-fat foods or microporous foams. Capillary suspensions have even recently been used to create porous ceramics with unprecedentedly high porosity and small pore sizes [2]. Previous investigations have shown that capillary suspensions transition to a gel-like state in micron-sized particles at volume fractions as low as φ = 0.10 – well below the limit of dense packing – increasing the yield stress and viscosity by several orders of magnitude as the volume of the second fluid increases. In the pendular state, the secondary fluid preferentially wets the particles and pendular bridges form between particles. The capillary force associated with such bridges is usually much stronger and dominates over other forces, such as the van der Waals force, leading to the formation of a sample-spanning network of particles bridged by the secondary fluid. In the capillary state, the volume between particles is filled with the secondary liquid. The typical size of these droplets is close to the particle size, such that that normalized volume Vl/r3 ≈ 1. This differs from Pickering emulsions where the droplet volume is typically much larger than the particle size, Vl/r3 >> 1. In the capillary state, macroscopic observations show that a samplespanning network has formed, but the underlying mechanism for such a network is not straightforward. This current research investigates the capillary state suspensions in more detail using a computational model to evaluate the lowest energy states of small particle number clusters. These clusters are used as building blocks for the formation of sample-spanning networks within the admixture, where the constituent structures have limited regions of stability based on the wetting angle and volume of the secondary fluid leading to changes in the strength of the network. The influence of the capillary force in the formation of these networks is further substantiated using rheological measurements. The strength of these mixtures demonstrate a dependence on the reciprocal particle radius, reduce in strength with increasing temperature (trending with interfacial tension), and are completely reversible if the secondary fluid is removed.

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References [1] [2]

E. Koos and N. Willenbacher, Science 331 (2011) 897. J. Dittmann, E. Koos, N. Willenbacher and B. Hochstein, German Patent DE 10 2011 106 834.5 (2011).

Figures

Figure 1: Transition from weakly elastic, fluid-like to highly elastic, gel-like state with the addition of small amounts of a second immiscible fluid as shown for hydrophobic calcium carbonate (Ď&#x2020; = 0.111) in diisononyl phthalate with less than 0.50% wt. distilled water.

Figure 2: Effect of added water on the yield stress and viscosity. (A) Normalized yield stress and (B) normalized viscosity at a single shear rate of Îł = 1 s-1, for various volume fractions of hydrophobic calcium carbonate in diisononyl phthalate. The yield stress in (B) and viscosity in (C) are normalized by the value at S = 1, where no water is present.

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Small is different: emergent fluid behavior in the nanoscale

63 Uzi Landman School of Physics, Georgia Institute of Technology Atlanta, GA 30332 USA Uzi.Landman@physics.gatech.edu When the scale of materials structures is reduced to the nanoscale, emergent physical and chemical behavior often occurs, that is not commonly expected, or deduced, from knowledge learned at larger sizes. Using computer-based simulations [1], often in conjunction with laboratory experiments, we highlight and illustrate such behavior in diverse emergent phenomena in nano-scale liquid systems. Topics that we discuss include: singly and multiply charged water nanoclusters, shape transitions and electrocrystallization of dielectric nanodroplets, trans-membrane transport processes via capillary nanojet injection of a liquid through bilayer membranes, and coexistence of correlated electron liquids and pinned Wigner crystals under high magnetic fields in the fractional quantum Hall effect regime, observed recently for 1/3 fractional filling, and its neighborhood, in 2D semiconductor quantum dots,

References [1]

U. Landman, â&#x20AC;&#x153;Materials by Numbers: Computations as Tools of Discoveryâ&#x20AC;?, Proc. Nat. Acad. Sci. (USA) 102, 6671 (2005).

* Work supported by the US Department of Energy and the Air Force Office of Scientific Research.

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TNT 2011

November 21-25, 2011

Tenerife - Spain

Nanostructured materials with biomimetic recognition abilities for chemical sensing Peter A. Lieberzeit, Thipvaree Wangchareansak, Renata Samardzic, Ghulam Mustafa, Sadia Bajwa University of Vienna, Department of Analytical Chemistry, Währinger Strasse 38, Vienna, Austria Peter.Lieberzeit@univie.ac.at Modern Materials Science takes some pride in implementing – sometimes complex – functionality into man-made matrices to make them suitable for a wide range of technological applications. Among other fields, materials being able to selectively and sensitively recognize species in their environments have become a strong focus of interest: Recognition is one of the key aspects of life governing a wide range of biological functions including immune reactions, but also catabolic and anabolic enzymatic processes to name the most important ones. Implementing such properties into an artificial material requires designing its functional and sterical features on the nanoscale finally leading to truly biomimetic setups. From the material chemist’s point of view, affinity interactions constitute one of the most straightforward possibilities for chemical sensing. It could already be shown that MoS2 nanoparticles interact with organic thiol vapors in air [1]. For understanding the underlying mechanisms better, they were coated on piezoelectric transducers, namely so-called quartz crystal microbalances (QCM). When exposed to different analytes, they yield a very distinct response pattern, as can be seen in the front column of data in Figure 1: the highest responses are achieved for octane thiol and butane thiol, respectively. For octane and the other analytes, the responses are at least a factor of two (butane thiol) and 25 (octane thiol) lower. Especially the selectivity between octane and octane thiol, respectively, is a strong indicative that recognition is indeed governed by the thiol functionality. Being a “soft” group on the Pearson hardness scale, further material optimization should focus on this parameter e.g. by changing the metal in the substrate material to Cu instead of Mo. Figure 1 shows the outcome of this approach, namely an almost threefold increase in sensor response for the thiols. This factor is lower for octane and one for the other analytes supporting the strategy of optimized affinity. Besides functionality, also sterical parameters can be addressed by smart materials structuring. Molecular imprinting [2] (see also Fig. 2) is a template-assisted strategy that leads to recognition cavities either in the bulk or on the surfaces of highly cross-linked polymer. The smallest possible analytes for their synthesis are given by metal ions. In this case, monomers that can form coordinative bonds allow for designing systems selectively interacting with bivalent copper ions, as can be seen from the QCM sensor responses summarized in Figure 2. Clearly, the imprinted material prefers the own template compound over all cross-reacting ones. This is even more remarkable keeping the fact in mind that there are only minute differences in the ionic radii of the compounds under observation. The method has proven very powerful also for volatile organics and their mixtures [3]. Further increasing the size of the analyte towards biospecies, the properties of molecularly imprinted polymers (MIP) can directly be compared to natural systems. An example for this is the imprinting with WGA lectin, a surface protein that plays an important role in infection pathways. In this case, the natural receptor group is an oligosaccharide with a glucosamine moiety. By adding a suitable linker group (p-nitrophenol reduced to the amine and then linked to cysteine), the receptor can be

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immobilized via self-assembled monolayers on a QCM surface yielding appreciable sensor characteristics. When comparing them to Molecularly imprinted polymers towards the same analyte, one can see that the nanostructured polymer yields selectivity that is only a factor two lower than the natural system. This generally speaking marks the way towards actual artificial antibodies. Inherently, the systems are also suitable for being applied for microorganisms. MIP for E. coli [4] on QCM are sufficiently robust to be applied over extended periods of time. Additionally, their interactions with the analyte are reversible. This makes them highly feasible tools for sensing immediately in bioreactors. During baceterial growth, the respective sensors indeed yield populationdependent sensor signals that can be vailidated by light microscopy. In contrast to antibodies, these artificial matrices can be regenerated and reused. Summarizingly, rationally structuring materials on the subnano- to micrometer scale results in biomimetic interaction behavior combined with the technological strengths of man-made substrates. References Lieberzeit PA, Afzal A, Rehman A, Dickert FL, Sens. Actuators B, 127 (2007) 132-136. a) Bossi A, Bonini F, Turner APF, Piletsky SA, Biosens. Bioelectron. 22 (2007) 1131-1137. b) Cooper MA, Uludag Y, Piletsky SA, Turner APF, FEBS 274 (2007) 5471-5480. Iqbal N, Mustafa G, Rehman A, Biedermann A, Najafi B, Lieberzeit PA, Dickert FL, Sensors 10 (2010) 6361-6371. Findeisen A, Wackerlig J, Samardzic R, Pitk채nen J, Anttalainen O, Dickert FL, Lieberzeit PA, Sens. Actuators B, in press. DOI: 10.1016/j.snb.2011.08.025.

[1] [2] [3] [4]

Figures 30

400

0 20

Sensor response (Hz)

Sensor Response [Hz]

-400

-800

Co(II)

Ni(II)

Zn(II)

-1200

Cu(II)-IPIII -1600

1-O c (30 tane pp thio m) l

MoS2 nanoparticles

NIP

Cu(II)

Cu2S nanoparticles n(50 Octa 0 p ne pm ) 1-B uta (50 n 0 p eth pm iol )

e en ) on pm m p Li 100 (

Et hy l (1 me 00 th 0 p yl pm ket ) one

100

Time (min)

Figure 1: QCM selectivity pattern of two different metal sulphide nanoparticles

Figure 2: QCM sensor responses of Cu(II) MIP towards competing bivalent ions.

Figure 3: Selectivity Pattern of Natural receptor analogue and WGA MIP, respectively.

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Low and fast magnetization dynamic driven by spin transfer torque in nanopillar spinvalve with strong perpendicular anisotropty Stéphane Mangin Institut Jean Lamour, CNRS, Nancy Universite´, UPV Metz, Vandoeuvre le`s Nancy, France stephane.mangin@ijl.nancy-universite.fr As predicted by L. Berger and J. Slonczewski [1] when a current of polarized electrons enters a ferromagnet the current exert a torque on the ferromagnet magnetization. This torque can lead to magnetization switching between two stable configurations which was later demonstrated in nanopillar spin-valve structures [2]. The ability of a spin-polarized current to reverse the magnetization orientation of nanomagnets should enable a range of magnetic devices such spin transfer magnetic random access memories (ST-MRAM). However, several advances are needed to realize practical devices [3]. One key point is the reduction of the currents required to switch magnetization while maintaining the thermal stability of the free layer. The study of the effect of both spin polarized current and thermal activation on magnetization dynamic as then been performed. Nanopillar spin valves 70 nm x 140 nm made of [Co/Ni] and [Co/Pd multilayers showing perpendicular anisotropy were prepared. In such geometry one can observe that the critical current scales with the height of the anisotropy energy barrier and critical currents as low as 120 mA is achieved in quasi-static room-temperature measurements of a 45-nm diameter device [4]. Moreover fast switching has been observed using short current pulses down to 300 ps [5,6] and thermally activated process gave rise to telegraph noise [7]. Fast magnetization precession could also be observed [8] We will also present results on the switching field distribution obtained by measuring the switching field of more that 1000 hysteresis loop for different injected current values. The results were treated in the light of a simple model of thermal activation over an energy barrier, first introduced by Néel and Brown [9]. The fitting of the switching field distribution using the Kurkijärvi expression [10] derivated from the Neel brown model permits to deduce the switching field distribution and the spincurrent-dependent energy barrier [11]. The study of the switching field distribution confirm that domain nucleation and growth need to be taken into account to fully explain the experimental observation as it can be seen on figure 1 [12] References [1] [2] [3] [4] [5] [6] [7]

L. Berger, Phys. Rev. B 54, 9353 (1996) J. Slonczewski, J. Magn. Magn. Mater. 159, L1 (1996) J. A. Katine et al Phys. Rev. Lett. 84, 3149 (2000)., E. B. Myers et al Science 285, 867 (1999). J. A. Katine and E. E. Fullerton, J. Magn. Magn. Mater. 320, 1217 (2008). ] S. Mangin, Y. Henry, D. Ravelosona, J. A. Katine, and Eric E. Fullerton, Appl. Phys. Lett. 94, 012502 (2009) D. Bedau, H. Liu, J. Z. Sun, J. A. Katine, E. E. Fullerton, S. Mangin, and A. D. Kent, Appl. Phys. Lett. 97, 262502 (2010) D. Bedau, H. Liu, J.J. Bouzaglou, A. D. Kent, J. Z. Sun, J. A. Katine, E. E. Fullerton, S. Mangin, Appl. Phys. Lett. 96, 022514 _2010_ J. Cucchiara, Y. Henry, D. Ravelosona, D. Lacour, Eric. E. Fullerton, J. A. Katine and S. Mangin Appl Phys. Lett 94 102503 (2009)

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[8]

[9] [10] [11] [12]

W. Lin, J. Cucchiara, C. Berthelot, T. Hauet, Y. Henry, J.A. Katine, Eric E. Fullerton and S. Mangin, Appl. Phys. Lett 96 252503 (2010) M. L. Néel, Ann. Geophys. 5, 99 (1949); W. F. Brown, Phys. Rev. B 130, 1677 (1963). J. Kurkijärvi, Phys. Rev. B, 6, 832 (1972). Z. Li and S. Zhang, Phys. Rev. B 69, 134416 (2004); D. M. Apalkov, D. M. and P. B. Visscher, Phys. Rev. B 72.180405 (2005). D. P. Bernstein, B. BrÄauer, R. Kukreja, J. StÄohr, T. Hauet, J. Cucchiara, S. Mangin, J.A. Katine, T. Tyliszczak K. W. Chou and Y. Acremann Phys rev B 83, 180410® (2011)

Figures

Figure 1: Experimental STXM images of the magnetic contrast in a 100 × 300 nm2 ellipsoidal nanopillar spin valve. Images (a)–(e) have been taken at different times during the CIMS reversal based on the setup shown in Fig. 1. Image (a) is the initial state, and (f) is the final state. The color scale corresponds to the perpendicular component of the free-layer magnetization, fromparallel (P)(red) to antiparallel (AP)(blue) with respect to the reference layer.

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Adsorption, cyclo-dehydrogentaion and graphene formation from large molecular precursors on catalytic surfaces J.A. Martín--Gago, G. Otero, A. Pinardi, P. Merino, M. Svec, M.F. López and J. Mendez Instituto Ciencia de Materiales de Madrid-CSIC Centro de astrobiología INTA-CSIC gago@icmm.csic.es Surface science techniques have shown their capability to follow in-situ chemical reactions on catalytic surfaces [1,2]. In this talk we will review the main mechanisms and strategies used to create new molecular structures and networks out of polycyclic molecular precursors. In particular we have studied the adsorption [3], cyclodehydrogentaion [4] and graphene formation [5,6] processes from C60H30 and C57N3H33, achiral polycyclic aromatic hydrocarbons (PAH), on different single-crystal transition metal surfaces by means of thermal under-vacuum annealing. The landing side of the molecule on a Pt(111) surface induces two chiral molecular forms on the surface, as seen by insitu scanning tunneling microscopy (STM) images. We show that the surface becomes enantioselective “recognizing” the landing side of an individual molecule. Thus, molecules adsorbed “right” or “left”-hand are differently split in two adsorption geometries, accordantly shifted [3]. Moreover, after annealing the adsorbed layer, a highly efficient (∼100%) dehydrogenation mechanism leads to a cyclodehydrogenation processes leading to the formation of fullerene C60 and for the first time triazafullerene C57N3 from their corresponding planar polycyclic aromatic precursors by a surface catalyzed process [4]. We have visualized the whole process by in-situ STM, XRay Photoemission spectroscopy, thermal desorption spectroscopy and DFT calculations. A 2D layer is formed. This layer is amorphous and weakly bound to the surface. The process is catalyzed very efficiently by Pt surfaces, which favors dehydrogenation, very poorly by Cu surfaces and it is mostly unsuccessful on Au surfaces. On this last surface a 2D layer is formed. This layer is amorphous and weakly bound to the Au underneath. Finally, extra annealing leads to molecular decomposition and to the formation of multiphase-graphene [5,6], where many different superstructures and Moirés can be found on the surface. Another question that will be touch is the capability for inducing dehydrogenation reaction of the oxide surfaces. These surfaces when reduced, present an electronic state within the gap, which could catalyze some reaction of large cyclic organic molecules. References [1] [2] [3] [4] [5] [6]

J. A. Martín-Gago. Nature Chemistry 3,11-12 (2011). J- Méndez et al.. Chem. Soc. Rev. 40, 4578–4590 (2011) G. Otero, et al.,Chem. Europ. J. 16,13920-13924 (2010) G. Otero et. al., Nature 454, 865-869 (2008). G. Otero et. al , Phys. Rev. Lett 105, 216102 (2010) P. Merino et al. ACS Nano, 5 (2011), 5627

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Figures

Figure 1: Schematic and simplified representation of an on-surface synthesis process. The deposited molecular precursors arrive to the surface and diffuse on it. In some cases, they could form an ordered SAM, which provides a pre-organization of the system. After a thermal treatment activated species can be formed. These species could lead either to surface organic frameworks (SOF) or being individually transformed into other different molecular species (nano-object), after for example, a surface assisted cyclodehydrogenation (SACDH) reaction.

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Cell behavior by the controlled immobilization of biotinylated proteins in a gradient fashion: non-linear concentration effects produced by unnoticed ligand nanoclustering E. Martíneza,b, A. Lagunasb,a, J. Comellesa,b, S. Oberhansla,b, E. Prats-Alfonsob,d, G. A. Acostab,d, F. Albericiod,e,b, J. Samitiera,b,c a

Nanobioengineering group, Institute for Bioengineering of Catalonia (IBEC),C/ Baldiri Reixac 10-12, 08028 Barcelona, Spain b Centro de Investigación Biomédica en Red. Bioingeniería, Biomateriales y Nanomedicina (Ciber-bbn), C/ María de luna 11, Edificio CEEI, 50018 Zaragoza, Spain c Department of Electronics, University of Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain dInstitute for Research in Biomedicine (IRB), Barcelona Science Park, C/ Baldiri Reixac 10-12, 08028, Barcelona, Spain e Department of Organic Chemistry, University of Barcelona, C/ Martí i Franquès 1, 08028, Barcelona, Spain emartinez@ibecbarcelona.eu Cell behavior onto bioengineered surfaces, in terms of adhesion, morphology, proliferation and differentiation, is affected by a number of variables including the former substrate derivatization process [1,2]. In this context, it is crucial to avoid uncontrolled exogeneous stimuli as far as possible by using surfaces with immobilized factors presented to the cell in a controlled way. Several examples of biomolecule immobilization strategies onto biomaterials have been described, involving both physical adsorption and chemical binding methods [3,4]. In general, chemical immobilization methods are preferred, since they provide a more stable link between the biomolecules and the biomaterial surface, thus avoiding uncontrolled desorption under physiological environments. However, strong and irreversible immobilization of sensitive biomolecules such as cytokines on surfaces often diminishes their biological functionality. Therefore, chemical immobilization has to ensure that the protein retains its biological activity. Moreover, it has been proven that cell response to many biomolecules is also dose-dependent, thus the biomolecule amount should be the optimal for maintaining its effective local concentration and extend its availability without a systematic risk of high dose. Therefore, it is of primary interest to find strategies that permit the correlation between the concentration of surface-bound growth factors and cell behavior. One of the strategies proposed for the systematic screening of the effects of surface-immobilized biomolecules is the use of the so called surface gradients, surfaces with a gradually varying composition along their length. They can be generated by different methodologies such as controlled diffusion, gradual immersion of the substrate in a reactive solution or microfluidic devices [5,6,7]. However, surface modification for biomolecule anchoring is often accompanied by changes of very relevant surface properties such as wettability, roughness or stiffness, making their effects very difficult to decouple from those coming from the bioactive motives introduced. This work describes a simple method for the construction of universal surface chemical gradient platforms based on the biotin/streptavidin model and its application in cell adhesion and differentiation studies [8]. In this approach, surface chemical gradients were prepared in poly(methyl methacrylate) (PMMA), a biocompatible polymer, by a controlled hydrolysis procedure. The resulting modified surfaces were extensively characterized in their physico-chemical properties. Chemical analysis carried out with time-offlight secondary ion mass spectrometry (ToF-SIMS) and X-Ray Photoelectron Spectroscopy (XPS) showed the formation of a smooth, highly controllable carboxylic acid increasing concentration gradient along the sample surface. Atomic Force Microscopy (AFM) and contact angle (CA) results point out that, in contrast with most of the chemical gradient methods published in literature, the chemical modification performed on the polymer surface barely affects its physical properties. The introduction of carboxylic acid functionality along the surface was then further used for biomolecule anchoring. For this purpose, the surface was allowed the subsequent activation and derivatization with biotin and finally, with streptavidin (SAV) in a directed orientation fashion. SAV gradient was qualitatively assessed by fluorescence microscopy analysis

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and, later on, quantified by Surface Plasmon Resonance (SPR) technique in order to establish a quantitative relationship between SAV surface densities and surface location. Such a gradient platform was first used to investigate the correlation between cell adhesion and celladhesive ligand surface concentration and organization due to substrate modification [9]. For this purpose, RGD gradient surfaces were created (Fig. 1). Cell culture shows that adhesion behavior changes in a nonlinear way within the narrow range of RGD surface densities assayed (2.8 to 4.4 pmol/cm2) with a threshold value of 4.0 pmol/cm2 for successful cell attachment and spreading (Fig. 2). This non-linear dependence may be explained by a non-homogeneous RGD surface distribution at the nanometer scale, conditioned by the stochastic nature of the hydrolysis process. Atomic Force Microscopy analysis of the gradient surface shows an evolution of surface morphology compatible with this hypothesis. Moreover, the gradient platform was also used to check effects of the concentration of Bone Morphogenic Factor 2 (BMP2) on the osteoblastic commitment of C2C12 cells in a single experiment. The narrow range of BMP-2 surface densities covered by the gradient allows for the precise tracking of the dose-guided activation of osteogenic markers Osterix (OSX) and Alkaline Phosphatase (ALP). A non-linear dependence of cell differentiation response with BMP-2 surface concentration has been found (Fig. 3). We hypothesize that BMP-2 ligands, pre-clustered on the surface due to the hydrolysis procedure, can favor ligand-receptor interactions, as reported with integrins, thus enhancing cell signaling. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

Langer, R.; Tirrell, D. A. Nature 2004, 428, 487-492. Lutolf, M. P.; Hubbell, J. A. Nat. Biotechnol. 2005, 23, 47-55. Maheshwari, G.; Brown, G.; Lauffenburger, D. A.; Wells, A.; Griffith, L. G. J. Cell. Sci. 2000, 113, 16771686. Reyes, C. D.; Garcia, A. J. J. Biomed. Mater. Res. A. 2003, 65, 511-523. Lieberg B, Wirde M, Tao Y-T, Tengwall P, Gelius U., Langmuir 1997; 13: 5329-5334. Baker BE, Kline NJ, Treado PJ, Natan MJ, J Am Chem Soc 1996; 118: 8721-8722. Caelen I, Bernard A, Juncker D, Michel B, Heinzelmann H, Delamarche E, Langmuir 2000; 16: 91259130. Lagunas A, Comelles J, Martínez E, Samitier J., Langmuir 2010; 26: 14154-14161. Lagunas A, Comelles J, Martínez E, Prats-Alfonso E, Acosta GA, Albericio F, et al., Nanomedicine: NBM (in press). Lagunas A, Comelles J, Oberhansl S, Martínez E, Samitier J, under review.

Figures

Figure 1: Scheme of the functionalization procedure followed to fabricate streptavidin gradients. Here, a biotinPEG-RGD molecule has been attached, but the platform provides a universal mechanism to create gradients of any biotinylated molecules.

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Figure 2: Cell adhesion in RGD-modified gradients. (a) Phase-contrast micrographs of NIH/3T3 mouse embryonic fibroblasts adhering to the RGDgradient surface after 1 h of incubation at 37°C (number of seeded 3 2 cells: 2 × 10 cells/cm , n = 3). Scale bar, 500 μm. (b) Number of cells adhering as a function of slide distance, showing a sharp increase in the cell adhesion number for RGD surface densities larger than 4.0 pmol/cm2.

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Figure 3: Tracking OSX activation and translocation into the cell nuclei as an effect of surface density. (A) Representative immunofluorescent images of C2C12 cells fixed and immunostained for OSX after 24h in culture at different positions on the BMP-2 gradient. Scale bar = 50 μm. (B) Plot of the OSX distribution percentages (selected following the Polak and coworkers criteria) as a function of the slide position (from the less hydrolyzed part of the slide). At least 30 cells were evaluated per selected region in three independent experiments.

Tenerife - Spain

Unusual nucleic acid structures: applications to nano- and biotechnologies

73 Jean-Louis Mergny INSERM U869, Univ. Bordeaux, ARNA Laboratory, Institut Européen de Chimie-Biologie, Pessac F-33600, France. Abstract Nucleic acids are prone to structural polymorphism: in addition to the well known DNA double-helix, a number of alternative structures may be formed. Several genetic diseases are mediated by the formation of non-B DNA structures at certain chromosomal locations. Among these oddities, a family of nucleic acid secondary structures known as G-quadruplexes (or G4) has emerged as more than a novelty. These structures can be formed by certain guanine-rich sequences and are stabilized by Gquartets. The evidence for quadruplex formation in vivo is now compelling. Our goals are now to conceive and validate new biochemical and physico-chemical tools for G-quadruplex studies. Introduction Since the discovery of the DNA double helix in 1953, a number of alternative structures have been proposed or demonstrated. While many of them are marginally stable under conditions mimicking the intracellular environment, DNA and RNA G-quadruplexes can be very stable in physiological conditions and the evidence for quadruplex formation in vivo is compelling. Comparison of sequencing data with theoretical sequence distributions suggests that there is a selection against Gquadruplex prone sequences in the genome, probably as they pose real problems during replication or transcription and generate genomic instability [1]. Nevertheless, “G4-hot spots” have been found in certain regions of the genome: in telomeres, in repetitive sequences such as mini and microsatellite DNAs, in promoter regions, and in first exons of mRNAs. There might be a specific positive role for these sequences that compensates for the general selection against G4 forming sequences. Our goals are to understand the factors that modulate these effects. We are developping G-quadruplexes to i) better understand the sequence requirements for G4 formation, ii) develop new G4 ligands and iii) apply quadruplex structures to nanotechnology. Results and Discussion I) Applications to nanotechnologies. DNA is an attractive material for nanotechnologies because of its self-assembly properties. The ability of nucleic acids to self-assemble into a variety of nanostructures and nanomachines is being exploited by a growing number of researchers. Extremely sophisticated structures and nanodevices may be constructed with DNA. We believe that quadruplex structures offer interesting new possibilities and we have demonstrated that quadruplexes can be incorporated into nanodevices and that mirror image quadruplexes may be obtained using L-DNA [2]. We can now assemble tetramolecular G-quadruplexes into well defined structures. An independent topic relates to the use of quadruplex DNAs as molecular beacons (MB). We previously demonstrated that a G4based MB outperforms a regular MB thanks to its differential ionic sensitivity [3]. II) Quadruplex ligands. Because of their particular geometric configuration and electrostatic potential, G-quadruplexes may indeed specifically accommodate proteins and small artificial ligands, such as planar molecules, and an impressive number of candidates have been evaluated [4]. Aptamers against a variety of targets adopt a quadruplex fold. Together with chemists from the Institut Curie in

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Orsay (M.P. Teulade-Fichou) we successfully identified a variety of G4 ligands. We are currently analyzing their specificity [5], mode of interaction and biological effects. We already have in hand very strong and highly selective ligands 6[]. We wish to improve and functionalize these compounds in order to perform additional functions such as i) emit fluorescence upon G4 binding [7] ii) allow streptavidin recognition, by covalent attachment of a biotin group to the G4 ligand [8] or iii) induce a covalent modification of the quadruplex due to the presence of chemically reactive groups. Acknowledgements This work was supported in part by the Aquitaine Regional Council, INCa, the Association pour la recherche sur le Cancer (ARC) the Fondation pour la Recherche Médicale (FRM) and ANR G4-Toolbox, QuantADN and F-DNA grants. References [1]

[2] [3] [4] [5] [6]

[7] [8]

(a) Ribeyre, C.; Lopes, J.; Boulé, J.-B.; Piazza, A.; Guédin, A.; Zakian, V. A.; Mergny, J.-L.; Nicolas, A., (2009) PLoS Genet. 5, e1000475; (b) Mendez-Bermudez, A.; Hills, M.; Pickett, H. A.; Phan, A. T.; Mergny, J. L.; Riou, J. F.; Royle, N., (2009) Nucleic Acids Research 37, 6225-6238. Tran, P. L.; Moriyama, R.; Maruyama, A.; Rayner, B.; Mergny, J. L., (2011) Chemical communications (Cambridge, England) 47, 5437-9. Bourdoncle, A.; Estévez-Torres, A.; Gosse, C.; Lacroix, L.; Vekhoff, P.; Le Saux, T.; Jullien, L.; Mergny, J. L., (2006) Journal of the American Chemical Society 128, 11094-11105. Monchaud, D.; Teulade-Fichou, M. P., (2008) Organic & Biomolecular Chemistry 6, 627-636. (a) Lacroix, L.; Séosse, A.; Mergny, J. L., (2011) Nucleic Acids Research 39, e21; (b) Tran, P. L.; Largy, E.; Hamon, F.; Teulade-Fichou, M. P.; Mergny, J. L., (2011) Biochimie 93, 1288-96. (a) Hamon, F.; Largy, E.; Guedin-Beaurepaire, A.; Rouchon-Dagois, M.; Sidibe, A.; Monchaud, D.; Mergny, J. L.; Riou, J. F.; Nguyen, C. H.; Teulade-Fichou, M. P., (2011) Angew. Chem. Int. Ed. 50, 8745-9; (b) Smith, N. M.; Labrunie, G.; Corry, B.; Tran, P. L. T.; Norret, M.; DjavaheriMergny, M.; Raston, C. L.; Mergny, J. L., (2011) Organic & Biomolecular Chemistry 9, 61546162. Yang, P.; De Cian, A.; Teulade-Fichou, M. P.; Mergny, J. L.; Monchaud, D., (2009) Angew. Chem. Int. Ed. 48, 2188-2191. Renaud de la Faverie, A.; Hamon, F.; Di Primo, C.; Largy, E.; Dausse, E.; Delauriere, L.; LandrasGuetta, C.; Toulme, J. J.; Teulade-Fichou, M. P.; Mergny, J. L., (2011) Biochimie 93, 1357-67.

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Enhanced spin contrast detection by spin-polarized scanning tunneling microscopy of antiferromagnetic Mn/Fe(100) films Puneet Mishra, Takashi Uchihashi, and Tomonobu Nakayama International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan MISHRA.Puneet@nims.go.jp Spin-polarized scanning tunneling microscopy/spectroscopy (SP-STM/S) is a powerful tool to investigate surface magnetism down to atomic scale [1]. To achieve a high spin contrast in the SPSTM images, the spin-polarization of the magnetic probe tip should be sufficiently large. Although there have been several proposals to enhance the tip spin-polarization, such as by using half-metallic magnetic materials, these are still not available for routine SP-STM applications. Recently, it was demonstrated that a controlled contact with a magnetic substrate, leading to a change in the magnetic tip apex structure, can alter the degree of tip spin-polarization [2]. An alternative approach for the tip modification would be by picking-up a magnetic atom or a small cluster from the sample surface which may also change the spin-polarization of the magnetic tip. However, this approach has not yet been utilized for the enhancement of the spin-polarization of a magnetic thin film tip. Here, we report on SP-STM investigations of Mn films grown on Fe(100) single crystal substrates using a magnetic thin film tip. We have observed a significantly enhanced spin contrast due to the tip modification, presumably caused by the attachment of a magnetic cluster at the tip apex [3]. This is supported by the observation of sharp peaks in the normalized dI/dV spectra which is attributed to the tunneling from d-like localized tip electronic states. These results are consistent with a recent theory which predicted a high vacuum spin-polarization of a Fe coated tip with a Mn apex adatom in the antiferromagnetic spin alignment [4]. Our study suggests that a controlled modification of magnetic thin film tips using atom manipulation technique [5] can provide a routine way to achieve high spin sensitivity in atomic scale magnetic imaging. References [1] [2] [3] [4] [5]

R. Wiesendanger, Rev. Mod. Phys. 81 (2009) 1495. M. Ziegler et al., Appl. Phys. Lett. 96 (2010) 132505. P. Mishra, T. Uchihashi, and T. Nakayama, Appl. Phys. Lett. 98 (2011) 123106. P. Ferriani, C. Lazo, and S. Heinze, Phys. Rev. B 82 (2010) 054411. S. Loth et al., Nat. Phys. 6 (2010) 340.

Figures

Figure 1: STM topographs (a, c) and dI/dV images (b, d) of two similarly grown 7.2 ML Mn films on Fe(100) substrate. The SP-STM measurements were carried out sequentially on the two samples (I and II) using the same magnetic tip. (e) The spin contrast variation as a function of sample bias voltage.

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Tenerife - Spain

Polarized recombination of acoustically transported charge carriers in GaAs nanowires

77 M. Möller1,2, A. Hernández-Mínguez2, S. Breuer2, C. Pfüller2, O. Brandt2, M. M. de Lima, Jr.1, A. Cantarero1, L. Geelhaar2, H. Riechert2 and P. V. Santos2 1

Insitut de Ciència dels Materials, Universitat de València, Catedrático José Beltrán 2, 46980 Paterna (València), Spain 2 Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, Berlin, Germany michael.moeller@uv.es

Semiconductor nanowires (NWs) offer new perspectives for low-dimensional semiconductor devices since the small radius favors mesoscopic size effects and lifts the epitaxial constraints associated with the growth of dissimilar materials. In addition, the geometry of NWs enables them to function as active device elements and interconnects, which can lead to highly integrated opto-electronic device structures. In this respect, the crystal structure of the NWs is of high importance since it controls the optoelectronic properties. For the full utilization of these favorable properties one needs to overcome the obstacles of electrical control fields, which normally requires doping and contacting of non-planar nm-sized structures, and the large surface-to-volume ratio, which often affects adversely the electronic properties. Here, we applied surface acoustic waves (SAW) to control remotely carriers in high quantum efficient GaAs/AlGaAs core-shell NWs. We have recently demonstrated that the oscillating piezoelectric field of a SAW can transport photoexcited charge carriers in GaAs NWs as well as control the spatial location of exciton recombination along the NW axis [1]. One important question is whether electron spins can be maintained during acoustic transport in NWs, as recently reported for spin diffusion in NWs [2]. In this contribution, we address this question by using polarization-resolved photoluminescence (PL) to detect the spin polarization of acoustically transported carriers in NWs. SAWs are propagating elastic vibrations confined to the surface of a material. On a piezoelectric semiconductor, these vibrations are accompanied by a piezoelectric potential ΦSAW, which traps electrons and holes in spatially separated positions, thus preventing their recombination. The acoustic fields allow to remotely control the PL intensity and to transport charge carriers and spins along the NW axis when it is parallel to the SAW propagation path. In this way, carriers generated on one edge of the NW can be transported by the SAW oscillating field to a remote position, where they recombine [1]. The studies were carried out on NWs with a diameter of 70 nm surrounded by a 15 nm-thick Al0.1Ga0.9As shell [3]. The NWs, which have predominantly a wurtzite structure, were dispersed on a LiNbO3 substrate containing a SAW delay line for an acoustic wavelength λSAW = 17.5 µm (frequency fSAW = 226 MHz). The acoustic charge transport experiments were performed at low temperature (20 K) by photo-generating carriers using a linearly polarized pulsed laser beam (pulse width of 150ps<<1/fSAW) tightly focused (1.5 µm spot diameter) onto one end of the NW and measuring the spatial distribution of the PL along the NW axis with polarization sensitivity. In the absence of acoustic excitation, the emission of the NWs takes place close to the illumination spot G and is mainly polarized perpendicular to the NW axis (see Fig. 1a). When a SAW is applied, the PL intensity at G reduces and a second PL spot, R, appears a few µm away from G along the SAW propagation direction (Fig. 1b). The latter is attributed to the acoustic transport of electrons and holes towards trap sites at R, where they recombine. This recombination is highly polarized parallel to the wire axis as can be seen in Fig. 1c.

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Although the emission characteristics at the G spot is consistent with the selection rules expected for wurtzite NWs, the emission at R shows a different polarization preference. Since the recombination of the transported carriers takes place at a trap, the selection rules can be different. The emission energy of approximately 818 nm suggests that the recombination center consists of a zincblende section at the nanowire extreme. The previous results show that the polarization of the PL does not depend on the incident laser polarization, thus implying that electron spins are not conserved during transport. To further support this conclusion, we carried out transport experiments where spin-down (σ-) electrons were generated on one extreme of the NW using left-handed circularly polarized light. The circular polarization of the PL was detected with spatial resolution using a λ/4 plate and a birefringence prism. Spatially resolved PL of incident left-handed circularly polarized light in absence and presence of a SAW are shown in Figs. 2a and 2b, respectively. In Fig. 2c and 2d the PL intensity along the NW axis integrated around 811 nm (Fig. 2c) and 818 nm (Fig. 2d) in the absence (solid lines) and presence (dashed lines) of a SAW for both spin states (σ+,σ-) are presented. Without acoustic power the PL is localized around 811 nm at the generation spot (Fig. 2a). When a SAW is applied, a second spot at the other extreme of the NW around 818 nm appears (Fig. 2b). Note that the emission intensity is equal for both circular polarizations (Fig. 2c,d), thus implying that the spin memory is lost during transport. References [1]

[2] [3]

A. Hernández-Mínguez, M. Möller, S. Breuer, C. Pfüller, C. Somaschini, S. Lazić, O. Brandt, A. García-Cristóbal, M. M. de Lima, Jr., A. Cantarero, L. Geelhaar, A. Trampert, H. Riechert, and P. V. Santos, submitted to Nano Letters. T. B. Hoang, L. V. Titova, J. M. Yarrison-Rice, H. E. Jackson, A. O. Govorov, Y. Kim, H. J. Joyce, H. H. Tan, C. Jagadish, L. M. Smith, Nano Letters, 7 (2007) 588. S. Breuer, C. Pfüller, T. Flissikowski, O. Brandt, H. T. Grahn, L. Geelhaar, and H. Riechert, Nano Letters, 11 (2011) 1276.

Figures Figure 1: (a,b) Spatially resolved PL excited by a linearly polarized laser beam tightly focused onto the NW edge facing the interdigital transducer used for SAW generation. The PL signal emitted along the NW axis is split by a birefringence prism into two orthogonally polarized rays. The rays with polarization parallel and perpendicular to the NW axis are then detected on the upper and lower regions of the PL images, respectively. (a) In the absence of a SAW the emission is restricted to the region close to the excitation spot and highly polarized perpendicular to the NW axis. (b) Application of acoustic power induces the transport of electrons and holes to a remote recombination spot, where they recombine emitting light polarized parallel to the NW axis. (c) Integrated PL intensity along the NW axis for the emission polarized perpendicular (blue circles) and parallel (red triangles) to the NW axis with (solid symbols) and without (open symbols) a SAW. Figure 2: Spatially resolved PL excited by a tightly focused, left-handed circularly polarized laser beam in the (a) absence and (b) presence of a SAW. As in Fig. 1a and 1b, the SAW fields quenches the PL signal at the illumination spot and leads to the appearance of a remote recombination spot 6 μm away for the generation spot. PL intensity along the NW axis with + left-handed (σ ) and right-handed (σ ) circular polarization integrated around (c) 811 nm (dashed line in 1a and 1b) and (d) 818 nm (dotted line). The solid and dashed curves were recorded in the absence (solid lines) and presence (dashed lines) of a SAW.

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Nematic Colloidal Crystals, Microresonators and 3D Microlasers for Soft Matter Photonics Igor Musevic1,2 1

J.Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia Faculty of Mathematics and Physics, University of Ljubljana, Jadraska 19, SI-1000, Ljubljana, Slovenia

igor.musevic@ijs.si We shall discuss general properties of nematic colloids, which are dispersions of microparticles in a nematic liquid crystal. A nematic liquid crystal is an orientationally ordered fluid, which interacts with the surfaces of inclusions. This interaction generates topological defects, which are responsible for structural forces between dispersed microparticles [1]. The structural forces in liquid crystals are extremely strong, anisotropic and long-range, and are responsible for self-assembly of a broad variety of colloidal superstructures in liquid crystals: 2D colloidal crystals [2], colloidal wires, assembled by entangled topological defects [3], superstructures in the mixtures of large and small colloidal particles [4] a broad variety of 2D nematic colloidal crystals [5] and colloidal knots and links [6]. In all cases, the colloidal binding energy is of the order of several 1000 kBT. It is therefore several orders of magnitude higher compared to water based colloids and could provide assembly of nanometer-sized colloidal particles [7]. It has recently been demonstrated, that several classes of tunable and active microphotonic devices could be realized in water or polymer-based dispersions of liquid crystals. When a nematic liquid crystal is dispersed in an insoluble isotropic media, like water or a polymer, nematic microdroplets are created that are excellent and highly tunable optical microresonators [8]. Light can be trapped in a microdroplet due to the total internal reflection and the resonant eigenmodes can be tuned by a relatively small external electric field over a tuning range of more than 20 nm. This could be a basic tunable optical resonant element for future soft matter photonic devices. It has been demonstrated in 2010 [9], that Bragg-onion optical microresonators could be created by simply dispersing a chiral nematic liquid crystal in water or polymer. 3D laser emission has been demonstrated from micrometer-sized chiral nematic droplets, where the wavelength tuning could be obtained over more than 200 nm range by changing the temperature of the material. Strategies for creating soft matter microphotonic devices and systems are discussed. Acknowledgement The author would like to thank Miha Škarabot, Miha Ravnik, Slobodan Žumer, Uroš Tkalec and Matjaz Humar. References [1] [2] [3] [4] [5]

P. Poulin, H. Stark, T. C. Lubensky, and D. A. Weitz, Science 1997, 275, 1770. I. Muševič, M. Škarabot, U. Tkalec, M. Ravnik, S. Žumer, Science, 2006, 313, 954. M. Ravnik, M. Škarabot, S. Žumer, U. Tkalec, I. Poberaj, D. Babič, N. Osterman, I. Muševič, Phys. Rev. Lett, 2007, 99, 247801. M. Škarabot, M. Ravnik, S. Žumer, U. Tkalec, I. Poberaj, D. Babič, I. Muševič, Phys. Rev. E, 2008, 77, 061706. U. Ognysta, A. Nych, V. Nazarenko, I. Muševič, M. Škarabot, M. Ravnik, S. Žumer, I. Poberaj, D. Babič, Phys. Rev. Lett, 2008, 100, 217803.

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[6] [7] [8] [9]

U. Tkalec, M. Ravnik, S. Čopar, S. Žumer, I. Muševič, Science 2011, 333, 62. F. R. Hung, Phys. Rev. E, 2009, 79, 021705. M. Humar, M. Ravnik, S. Pajk, I. Muševič, Nature Photonics 2009, 3, 595. M. Humar and I. Musevič, Opt. Express 2010, 18, 26995.

Figures

Figure 1: 2D nematic colloidal crystal, assembled from 2.3 µm silica microspheres in a nematic liquid crystal 5CB. The microspheres are bound together by an array of topological defects. Topological defects are responsible for a fascinating variety of colloidal assemblies in liquid crystals.

Figure 2: Nematic colloidal wire, assembled from 2.3 µm silica microspheres in a nematic liquid crystal 5CB. The microspheres are bound together by entangled defect lines, which are wrapped around the microspheres. The bottom image shows the results of Landau-de Gennes simulations.

Figure 3: A single droplet of a nematic liquid crystal 5CB, which is embedded into a low refractive index polymer matrix, is an optical microresonator. Light is circulating inside the droplet due to total internal reflection at the interface. The resonant frequencies of these Whispering Gallery Modes can be tuned by an external electric field, which modifies the index of refraction of a liquid crystal. The range of tuning is nearly two orders larger compared to solid state devices.

Figure 4: A single droplet of a cholesteric liquid crystal doped with a fluorescent dye and immersed in water or other immiscible liquid is a 3D microlaser. Because of chirality, the LC molecules form a helical birefringent structure, originating at the center and spiraling to the surface. Optically, this is a spherical, onion-Bragg microresonator. When pumped with external light, the 3D microlaser starts emitting coherent light in 3D.

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Biological synapse mimicked in an inorganic Cu2S gap-type atomic switch Alpana Nayak1, Takeo Ohno1, Kazuya Terabe1, Tohru Tsuruoka1, Tsuyoshi Hasegawa1, James K. Gimzewski1,2,3 and Masakazu Aono1 1

International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan, 2 Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), 607 Charles E. Young Drive East, Los Angeles, California 90095, USA, 3 California NanoSystems Institute (CNSI), University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095, USA. NAYAK.Alpana@nims.go.jp A gap-type atomic switch1, which operates by formation and annihilation of Cu atomic bridge across a nanogap between a Cu2S solid-electrolyte electrode and an inert metal electrode (Pt), exhibits interesting characteristics with analogies to an individual biological synapse. Application of input voltage pulses (stimuli) causes precipitation of Cu atoms from the Cu2S electrode due to a solid electrochemical reaction, resulting in the formation of the Cu atomic bridge. Consequently, the conductance between the Cu2S and Pt electrodes increases. The switch shows two types of conductance states: first, a temporary increase in conductance followed by spontaneous decay over time achieved by input stimuli at a lower repetition rate, and second, a persistent enhancement of conductance achieved by a frequent input stimuli repetition. These two states are analogous to the short-term plasticity (STP) and long-term potentiation (LTP) states, respectively, in a biological synapse wherein a persistent increase in the synaptic strength is achieved following a higher repetition stimulation by action potentials (Figure 1(a)). Similar behavior has also been observed in an Ag2S gap-type atomic switch recently2,3. We explain these conductance states in terms of the atomic bridge formation and its stability. In our inorganic STP state, the precipitated Cu atoms do not form a complete bridge (Figure 1(b)) and the higherconductance of approximately one quantized channel (1G0= 2e2/h =77.5 ÂľS) is not maintained after each input pulse (Figure1 (c)). On the other hand, in the LTP state, a complete and robust atomic bridge is formed (Figure 1(b)) and a conductance higher than 77.5 ÂľS is maintained after the last input pulse (Figure 1(d)). Changes in conductance, including transition between these two states, depend on temperature and strength of the input stimuli. For instance, by increasing temperature and the pulse amplitude and width, the number of input pulses required to attain a LTP state reduces drastically. Compared with Ag2S, the Cu2S system needs input pulses of higher amplitude because of its higher activation energy for the chemical reaction. However, both of the inorganic synapses achieve dynamic memorization in a single device without the need of external preprogramming. In addition, the variation depending on the materials will enable us to develop more complex circuit elements which may lead to the construction of artificial neural networks for computing applications. References [1] [2] [3]

K. Terabe, T. Hasegawa, T. Nakayama, and M. Aono, Nature, 433 (2005), 47. T. Hasegawa, T. Ohno, K. Terabe, T. Tsuruoka, T. Nakayama, J. K. Gimzewski, and M. Aono, Adv. Mater. 22 (2010),1. T. Ohno, T. Hasegawa, T. Tsuruoka, K. Terabe, J. K. Gimzewski, and M. Aono, Nature Materials, 10 (2011), 591.

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Figures

Figure 1: (a) In a biological synapse, the release of neurotransmitters is caused by the arrival of action potentials and then a signal is transmitted as a synaptic potential. Frequent stimulation causes long-term enhancement in the synaptic strength. (b) Schematic of a Cu2S inorganic synapse showing short-term plasticity (STP) and long-term potentiation (LTP) states depending on the input-pulse repetition time (T).When the precipitated Cu atoms do not form a complete bridge between the Cu2S and Pt electrodes, the inorganic synapse works as STP. After a complete and robust atomic bridge is formed, it works as LTP. (c-d) Change in the conductance of the inorganic synapse when the input pulses (amplitude (V) = 150 mV, width = 500ms) were applied with intervals of T =10 s (c) and 1 s (d). 2 The conductance of the inorganic synapse with a single atomic contact is given by G0=2e /h=77.5 ÂľS.

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Graded exchange spring media based on FePt

83 D. Niarchos*, Th. Speliotis, G. Giannopoulos 1

IMS, NCSR Demokritos, Aghia Paraskevi, Attikis, Athens 15310, Greece

Abstract We present data related to the advantages that Graded Exchange Spring Media (G-ESM) offer to tailor the coercivity of the fct-FePt films, which are the best candidates for the future recording media in excess of 1 Tbit/in2. By varying the thickness and the anisotropy of the “soft” fcc-FePt we have achieved a reduction of the switching field from the value of 3.5 T for the hard single fct-FePt layer to a value less than 1 T, suitable for recording with existing GMR heads. Introduction Future recording media must have high anisotropy in order to beat the superparamagnetic limit due to the reduction of bit size in the sun-10nm range. A material with the best so-far properties as a candidate magnetic layer for perpendicular magnetic recording is the fct-FePt with anisotropy constants in excess of 10 MJ/m3. The high coercivity field (Hc > 3T) of these materials makes difficult the writing process using the available magnetic write heads. Solutions to these problems are the Heat Assisted Magnetic Recording approach or a novel type of Exchange Spring Media (ESM) [1]. In the ESM media a magnetically hard layer (high anisotropy Ku) and a magnetically softer layer (lower anisotropy Ku) are strongly exchange coupled leading to structures with lower Hc thus lowering the write field requirements. A better approach for reducing more the writing field but keeping the thermal stability very high is the class of Graded Exchange Spring Media, which have been proposed as a new class of nanocomposite material appropriate for ultra high density recording media [2] (Goll, APL 2010, APL 2011). Graded ESM with a spatially varying anisotropy Ku(z) offer improved characteristics in comparison to homogeneous, constant Hard / Soft bilayer media. Experimental Single and graded exchange spring media were prepared by magnetron sputtering from a single FePt target on single crystal MgO (001) substrate. First we deposited a single hard fct-FePt layer wit a thickness of 1- nm with a coercivity of 3.8 T . On top of such a film by changing the deposition temperature we deposited continuously, with the same sputtering conditions, a film of thickness up to 30 nm. With such a procedure we managed to change the anisotropy constant Ku(z) reaching an fcc-FePt value when the terminal temperature was below 200 0C (Fig. 1.). We have prepared a series of samples by varying the Ku(z) either by using stacks of FePt layers with different anisotropy constants – deposited at different substrate temperatures in a graded fashion or by co-depositing FePt at predetermined temperatures. This approach produces a monotonic gradient of the anisotropy constant through the thickness of the layer in a more controlled fashion with no interfaces. Results In Fig. 1a the ideal graded ESM media is shown and in Fig. 1(b) a schematic of one bit of graded media is shown with Ku(z) variation. In Fig. 2a the ideal and realistic structure is shown based on TEM results as in Fig. 2b. Lee et al. , using the model of Fig. 2a has calculated , using micromagnetic calculations and for different Ku(z) profiles, and the results are shown in Fig. 5. In Fig. 4 we show the experimental data of our samples , which confirm the modeling results. The films were characterized using XRD, GID, TEM, AFM, MFM. The first results showed that the switching field is significantly reduced compared to single phase media, verifying the theoretical calculations [3, 4].

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Conclusions In conclusion, it was shown that the phase graded media consisting of only two phases fct-FePt/ fccFePt can be used to tailor the coercivity of the hard fct-FePt films and considerably decreased the switching field by introducing rough interface between the two phases. By controlling the interface between the hard/soft and using various types of modification of the Ku(z) we can optimize not only the switching field but also interdiffusion of the two phases, the pinning and nucleation fields.

The authors would like to thank J. Lee and J. Fidler from TUW, Austria, for valuable contributions in the modelling and microstructure studies. Work supported by the ICT-22401-TERAMAGSTOR Project of the EU. References [1] [2] [3] [4] [5] [6]

D. Suess, K. Porath, J. Fidler, and T. Schrefl, Transact on Magn 42, 2357 (2006) D. Goll and S. Macke, Appl. Phys. Lett. 93, 152512 (2008). V. Alexandrakis, Th. Speliotis , E. Manios , D. Niarchos , J. Fidler , J. Lee , G. Varvaro , J. Appl. Phys. 109 (7), 07B729 (2011) J. Lee, V. Alexandrakis, M. Fuger, B. Dymerska, D. Suess, D. Niarchos, and J. Fidler, Appl. Phys. Lett. 98, 222501 (2011)

Figures

Figure 1: (a)Model graded ESM (left) , (b) Realistic structure of exchange spring media (right)

Figure 2: The ideal and realistic structure (left picture) (b). HRTEM-TEM image Hc Exponential cooling Hc linear cooling

3.0

Switching field (T)

2.5 2.0 1.5 1.0 0.5 0.0

Thickness tg (nm)

Figure 3: Variation of switching field with the temperature profile

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Figure 4: Experimental data of linear and exponential cooling

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Beating the size limits of first-principles calculations in nanoscale systems

85 Pablo Ordejón Centre d'Investigació en Nanociència i Nanotecnologia - CIN2 (CSIC-ICN), Campus de la UAB, 08193 Bellaterra, Barcelona , Spain pablo.ordejon@cin2.es The advances in the predictive power, speed and reliability of ab-initio methods has occurred in the last few decades at a very fast pace. Simultaneously, the computing power available through HPC facilities has continued growing exponentially. This combination has brought the paradigm of ab-initio simulations as an invaluable tool to understand and predict the behavior of matter at the nanoscale. First-principles electronic structure methods have advanced in their efficiency to the point where realistic simulations can now be done for systems with many hundreds of atoms [1]. Besides, these methods have been successfully extended to deal with nonequilibrium processes such as electronic transport [2]. Current-voltage characteristics for systems as large as several hundreds of atoms, as those shown in Figure 1, can be currently studied a the fully atomistic and first-principles level [3]. However, enormous challenges are still ahead of us, to be able to extend the range of practical applicability of these methods to the sizes and time scales which are relevant to most of the practical problems in nanotechnology. For instance, many of the processes and properties that make graphene an outstanding material for potential applications are still beyond the reach of these methods, due to the large length or time scales involved. One example is electronic transport, in which the scattering lengths involved are so large that straight first-principles transport calculations are not relevant, because they can still not reach the appropriate length scales. In this talk I will review work done in our group in using first-principles methods for the study of graphene (including electronic transport [3]), and efforts to extend these studies to reach larger length and time scales. In particular, I will describe an implementation of a hybrid QM/MM approach [4] and its application to the immobilization of proteins on graphite surfaces decorated with gold nanoclusters. I will also illustrate the use of first-principles calculations to obtain tight-binding parameters that can be used to compute the transport properties of large samples of chemically modified graphene [5-7].

References [1] [2] [3] [4] [5] [6] [7]

J.M. Soler, E. Artacho, J. Gale, A. García, J. Junquera, P. Ordejón and D. Sánchez-Portal, J. Phys.: Cond. Matt. 14, (2002) 2745. M. Brandbyge, J.L. Mozos, P. Ordejón, J. Taylor and K. Stokbro, Phys. Rev. B 65, (2002) 165401. F.D. Novaes, R. Rurali and P. Ordejón, ACS Nano 4, (2010) 7596. C. F. Sanz-Navarro, R. Grima, A. García, E. A. Bea, A. Soba, J. M. Cela and P. Ordejón, Theoretical Chemistry Accounts 128 (2011) 825. N. Leconte, J. Moser, P. Ordejón, H. Tao, A. Lherbier, A. Bachtold, F. Alsina, C.M. SotomayorTorres, J.-C. Charlier and S. Roche, ACS Nano 4 (2010) 4033. N. Leconte, D. Soriano, S. Roche, P. Ordejón, J.-C. Charlier and J.J. Palacios, ACS Nano 5 (2011) 3987. D. Soriano, N. Leconte, P. Ordejón, J.-C. Charlier, J.J. Palacios and S. Roche, Phys. Rev. Lett. 107 (2011) 016602.

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Figures

Figure 1: Pictorial representation of a device consisting in an array of carbon nanotubes linking two semi-infinite graphene sheets. The electronic properties of these arrays were studied using first-principles calculations in Reference [3]

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Formation of thick dielectrophoretic carbon nanotube fibers

87 Margo Plaado, Robert Matias Mononen, Rünno Lõhmus, Ilmar Kink, Kristjan Saal. Institute of Physics, University of Tartu, Riia 142, 51014, Tartu, Estonia. plaado@fi.tartu.ee The development of carbon nanotube (CNT) fiber technologies is motivated by the promise of obtaining thread-like micro- and macro-scale structures that carry a significant fraction of the extraordinary mechanical and electrical properties of individual CNTs. In the case of dielectrophoresis (DEP), the fiber is drawn from a CNT suspension with an ultrasharp metal needle while applying an AC voltage between the needle and the substrate where the suspension droplet rests [1].

Figure 1: SEM image of dielectrophoresis grown CNT fiber.

The aim of this work was to elucidate the formation process of dielectrophoretic carbon nanotube fibers (CNT-fibers) and characterize the fiber properties relevant to their technological applications. The fiber diameter was shown to increase when applied voltage was increased (up to 350 Vpp) and when retraction speed was decreased (down from 400 μm s−1) in accordance with theoretical expectations. This work represents the first demonstration of the formation of thick DEP CNT-fibers (up to 0.4 mm in diameter). This is an intriguing result, as it expands the diversity of possible applications of the fibers and facilitates their characterization by analytical methods that require large quantities of the material.

The performance of these thick fibers was as follows: a density of ~0.35 g cm−3, a tensile strength of ~15 MPa, a Young’s modulus of ~1 GPa, and an electrical resistivity of ~70 mΩ cm [2]. Acknowledgements This work was supported by the Estonian Science Foundation grant no 8420, 8428, Eurocores Fanas Nanoparma Program, Estonian Nanotechnology Competence Center and by graduate school „Functional materials and processes“ receiving funding from the European Social Fund under project 1.2.0401.09-0079 in Estonia. References [1] [2]

Tang J, Gao B, Geng H Z, Velev O D, Qin L C and Zhou O 2003 Adv. Mater. 15 1352 Plaado M, Mononen R M, Lõhmus R, Kink I and Saal K 2011 Nanotechnology 22 305711

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Lithographically Defined Nanostructures for Biological Sensing Applications

89 Ronen Polsky,a Xiaoyin Xiao,a Cody M. Washburn,a David R. Wheeler,a Susan M. Brozik,a Thayne L. Edwards,a Sirilak Sattayasamitsathit, b Aiofe M Oâ&#x20AC;&#x2122;Mahoney,b Joseph Wang,b Phillip R. Miller,c Roger J. Narayan,c and D. Bruce Burckela rpolsky@sandia.gov (a) Biosensors & Nanomaterials, Sandia National Laboratories, PO Box 5800 MS 0892 Albuquerque, NM, 87185-0892, USA (b) Department of Nanoengineering, University of California, San Diego, La Jolla, California, 92093 USA (c) UNC/NCSU Joint Department of Biomedical Engineering, 911 Oval Drive Campus Box 7115, Raleigh, NC 27695-7115 USA The use of various photopatterning techniques to create micro/nano structured electrodes is described: Porous carbon electrodes are fabricated by interferometric lithography (IL) to generate 3-D periodic structures in pyrolyzed photoresist that contain five patterned layers with microporous hexagonal lattices (~ 800 nm in diameter). [1] Because IL is a maskless approach porous carbon structures are able to be produced with defect-free 3-D lattices and sub-wavelength periodicity uniformly over samples in excess of 2 cm a side. Despite a high degree of interconnectivity, the relatively large pore sizes preserve hemispherical diffusion inside the structures which exhibit diffusion profiles similar to microelectrodes. [2] We demonstrate that these porous carbon structures can be used as a highly adaptable electrode material for the deposition of metal nanoparticles and conducting polymers with possible applications in biological and chemical sensors. Direct writing patterning techniques, such as stereolithography and two photon polymerization are then used to create hollow bore microneedles that can be integrated with carbon fiber or carbon paste electrodes for transdermal sensing applications. The detection of ascorbic acid, hydrogen peroxide, glucose, lactate, and pH with these devices will be presented with an emphasis on characterizing microenvironments due to metabolic acidosis. References [1] [2]

a) D. B. Burckel, C. M. Washburn, A. K. Raub, S. R. J. Brueck, D. R. Wheeler, S. M. Brozik, and R. Polsky Small 2009 5, 2792-2796. X. Xiao, M.E. Roberts, D.R. Wheeler, C.M. Washburn, T.L. Edwards, S.M. Brozik, G.A. MontaĂąo, B.C. Bunker, D.B. Burckel, R. Polsky, ACS Appl. Mat. and Inter., 2010 2, 3179-3184

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Parallel Arrays of Silicon-Nanowire Field Effect Transistors for Nanoelectronics and Biosensors Sebastian Pregl1,2, Walter Weber2, Jörg Opitz3, Thomas Mikolajik2, Gianaurelio Cuniberti1 Institute for Materials Science and Max Bergmann, Center of Biomaterials, Dresden University of Technology, D-01069 Dresden, Germany NaMLab GmbH, D-01187 Dresden, Germany Fraunhofer Institute IZFP Dresden, D-01109 Dresden, Germany sebastian.pregl@nano.tu-dresden.de Silicon nanowires have great potential in the fields of bio chemical sensing and nanoelectronics due to their high sensitivity. However, single nanowire devices suffer from low current outputs. This work focuses in transistors made of parallel nanowire arrays that combine sufficient sensitivity with adequate current levels. Intrinsic silicon nanowires, grown by catalytic chemical vapor deposition (CVD), show electronic transport characteristics determined by the contact resistance [1]. For silicon nanowires contacted to nickel, annealing leads to axial silicidation. This results in a sharp metalsemiconductor interface which gives a fixed Schottky-barrier height along the entire contact area [2]. These wires are used as Schottky-barrier field effect transistors (SB-FETs). On/off current ratios up to 107 are observed for these devices. However, currents of a single nanowire FET with diameter of 20 nm are limited to approximately 1 µA and are too low for a practical sensor implementation. To enhance the maximum output current and to profit from statistical averaging, parallel arrays of nanowire SB-FETs are produced. Contact printing technique is used to transfer nanowires from the growth substrate to the chip substrate with high density and pre-defined/controlled orientation [3]. Nanowires are contacted afterwards with interdigital electrode structures by lithographical means. Significant enhancement of on-currents could be reached with these parallel arrays (0,2mA at 0.5V source drain voltage). At the same time the off-currents degrade, however the on/off current ratio is 103. The device fabrication with few process steps has a yield close to one which makes it feasible for commercialization. Such high-current-FET systems are appropriate for sensor systems with high readout currents and large active sensor area. References [1] [2] [3]

W Weber, G Duesberg, et al., phys.stat.sol.(b) 2006, 1-6 W Weber, L Geelhaar et al., Nano Letters, 2006 Vol6 No12, 2660-2666 Zhiyong Fan et al., Nano Letters, 2008 Vol8 No1, 20-25

Figures

Figure 1: (SEM image) Interdigitated electrode structures (Ni) on 200nm thermal silicon oxide contacting silicon nanowires.

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Figure 2: (SEM image) Several nanowires with intruded Nickel contacts in parallel. “Fingers” form alternating source and drain contacts. Parallel nanowire-SB-FETs are controlled via back gate.

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Microscopic modeling of charge transport in sensing proteins

93 Lino Reggiani, Eleonora Alfinito, Jean-Francois Millithaler and Cecilia Pennetta Dipartimento di Ingegneria dell'Innovazione and CNISM, UniversitĂ del Salento, Via Arnesano s/n, 73100 Lecce, Italy lino.reggiani@unisalento.it Sensing proteins (receptors) are very intriguing materials. From one hand, they are quite small structures (about 5 nm diameter ) and exhibit very complex behaviors (they can â&#x20AC;&#x153;pumpâ&#x20AC;? ions, use energy from the environment, change their shape, catalyze some reactions, etc). From another hand, they control the life of any organism at a cellular level. All of them are constituted by a specific sequence (several hundreds) of amino-acids (primary structure) and in this sequence the space organization (tertiary structure) is codified. Functioning of these macromolecules is intrinsically connected to their tertiary structure, and modifications in the former induce modifications in the latter; the reverse also happens. Most of protein receptors operate with a lock-and-key mechanism [1]. They possess an active site (lock) in which only few specific molecules (keys) can be attached. For some of them the specialization is so high that only one key is accepted, for example a photon. The key produces relevant modifications of the tertiary structure, which, in turn, are responsible for the protein functioning in the living system. With the advance of nanotechnology, the investigation of the electrical properties of sensing proteins has emerged as a demanding issue. Beside the fundamental interest, the possibility to exploit the electrical properties for the development of bio-electronic devices of new generations has attracted major interest of many researchers. From the experimental side we cite three significant experimental approaches: (i) current voltage (I-V) measurements in nanometric layers of a given protein sandwiched between macroscopic (mm^2) contacts, (ii) I-V measurements within an AFM environment in nanometic monolayers of a given protein deposited on a conducting substrate, (iii) electrochemical impedance spectroscopy (EIS) on appropriate monolayers of self-assembled samples of a given protein. From a theoretical side, a microscopic interpretation of these experiments is still a challenging issue. The aim of this talk is to address the above issue by reviewing recent theoretical results carried out by the Authors within an Euroean project,BOND (Biosensor 0lfactory Neuron Devices) [2], which provide a first quantitative interpretation of the three kinds of charge transfer experiments detailed above. As significant examples, Figs. 1 and 2 compare different sets of experiments carried out on bacteriorhodopsin (a light receptor) and rat I7 (an olfactory receptor) with the corresponding theoretical modeling, showing the reasonable good agreement obtained. Details of the model as well as the potential applications of this research will be addressed at the Conference. This research is carried out within the bioelectronic olfactory neuron device (BOND) project sponsored by the CE within the 7th Program, grant agreement: 228685-2.

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References

[1] [2]

[3]

The lock-and-key theory is very old, it was revised in 1958 by D.E. Koshland Jr in the paper: Application of a theory of enzyme specificity to protein synthesis, PNAS 44, 98-104 (1958). More information on the project can be found at the web site: http://bondproject.org/ . See also: E. Alfinito, C. Pennetta, L. Reggiani, First evidences supporting the realization of smell nanobiosensors based on olfactoryâ&#x20AC;ŚSensors and Actuators B: Chemical, 146 , 554-558 (2010); E. Alfinito, J.-F. Millithaler, C. Pennetta, L. Reggiani, A single protein based nanobiosensor for odorant recognition, Microelectr. Journal. 41, 718 (2010). E. Alfinito, L. Reggiani, Charge transport in bacteriorhodopsin monolayers, Europhys. Lett. 85. 6802(1-6) (2009).

Figures

Figure 1: I-V characteristics for the native and activated state of bacteriorhodopsin [3]. Calculations (symbols) have been performed using a tunneling mechanism for charge transfer with a single value of barrier height (upper part of figure) and with a Gaussian distributed set of heights (lower part of figure. In both the cases the full squares refer to the native state, while the empty squares refer to the activated state. Dashed curves refer to experiments, the lower for the native state (in dark) the higher for the activated state (in the presence of a green light).

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Figure 2: Nyquist plots for the native and activated states of the rat olfactory receptor I7 [3]. The continuous line reports the calculations for the native state, and the dashed line for the activated state when choosing an interacting radius between aminoacids of 20 A. The experimental resolutions obtained with an odorant concentration of 10-4 M for the two specific ligands, octanal and heptanal, are pointed out by the arrows.

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Dynamic Helical Polymers: Sensors for the Valence of Metal Cations

95 Ricardo Riguera, Félix Freire, José Manuel Seco, Emilio Quiñoa Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela, Santiago de Compostela, España. ricardo.riguera@usc.es The design, synthesis and applications of helical polymers with a controlled helix sense has become a field of major interest in the last decade.[1,2] The possibility of controlling and switching the helicity of these polymers by an external stimulus (temperature, solvent, light...)[1] makes them good candidates for their use as chiral sensors, molecular devices, chirooptical switches, memory elements for information storage, chiral catalyst and conductive materials.[1,2] Our research group has recently demonstrated that it is possible to reverse the helix sense of a polyphenylacetylene bearing chiral pendants by adding metal salts. [3] Now we present a highly dynamic helical polymer with a novel chiral pendant[4] which presents an inactive CD spectrum. The selective interaction of the polymer with mono- and divalent metal cations induces a right or left handed helical sense of the polymer by a chiral amplification phenomenon. References [1] [2]

[3] [4]

Eiji Yashima, Katsuhiro Maeda, Hiroki Iida, Yoshio Furusho, and Kanji Nagai, Helical Polymers: Synthesis, Structures, and Functions, Chem. Rev., 2009, 109, 6102-6211. Sierra T.; Expresion of Chirality in Polymers. In Chirality at the Nanoscale: Nanoparticles, Surfaces Materials and more; ed by D. B. Amabilino, 2009, Wiley-VCH, Verlag GmbH & Co-. KGaA, Weiheim, Chap 5, pp 115-190. Louzao, I.; Seco, J. M.; Quiñoá, E.; Riguera. R. Angew. Chem. Int. Ed. 2010, 49, 1430- 1433. Freire, F.; Seco, J. M.; Quiñoá, E.; Riguera. R. Angew. Chem. Int. Ed. 2011, DOI: 10.1002/anie.201105769.

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Transport Properties in Disordered Graphene : Effects of Atomic Hydrogen and Structural Defects

Stephan Roche Catalan Institute of Nanotechnology (ICN)-CIN2 Theoretical & Computational Nanoscience Group stephan.roche@icn.cat Group webpage http://www.icn.cat/index.php/en/research/core-research/theoretical-and-computationalnanosience/overview This talk will focus on the presentation of transport properties in graphene-based-materials, driven by chemical functionalization and structural defects. To circumvent the current hurdles preventing the advent of graphene nanoelectronics, it has become urgent to benefit from engineering complexity at the nanoscale and the unique potential of graphene as a bridging platform between top-down conventional CMOS technologies and (bio)-chemistry self-assembling processes. Here, by using state-of-the-art multiscale simulations (combining first-principles with tightbinding schemes), we present several electronic transport features in complex forms of chemically modified graphene based materials. Past Figure 1: Magnetoresistance of a weakly hydrogenated examples include the use of boron or nitrogengraphene sample predicted numerically. doped to produce graphene-based nanoribbons exhibiting â&#x20AC;&#x153;mobility gapsâ&#x20AC;? of width as large as 1eV, providing an efficient switching behavior principle even in the presence of a vanishing electronic band-gap. The possibility to design a switching effect based on mechanical deformation of graphene nanoribbons. Here, we will explore the effect of atomic hydrogen driving intrinsic magnetic ordering will be presented from a theoretical perspective and in comparison with most recent experiments. It will be shown that the existence of a long range ferromagnetic state in weakly hydrogenated graphene could be related to a highly robust metallic state down to cryogenic temperatures, in contrast to the localization regime obtained in absence of ferromagnetic order. Additionally, the possibility to observe measurable magnetoresistance signals due to magnetism in graphene will be discussed. As a second issue, the presence of structural defects will be shown to yield conventional localization effects.

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Related bibliography

Mark H. Rümmeli et al., Graphene: Piecing it Together, Advanced Materials, 23, 4471–4490 (2011) F. Ortmann, A. Cresti, G. Montambaux and S. Roche, Magnetoresistance in disordered graphene: The role of pseudospin and dimensionality effects unravelled, European Physics Letters, 94, 47006 (2011) D. Soriano, N. Leconte, P Ordejon, J.-Ch. Charlier, J.-J. Palacios, and S. Roche, Magnetoresistance and Magnetic Ordering Fingerprints in Hydrogenated Graphene, Physical Review Letters 107, 016602 (2011) A. Lherbier, S.M.M. Dubois, X. Declerck, Sr. Roche, Y.-M. Niquet and J.C. Charlier, Two-dimensional Graphene with Structural Defects: Elastic Mean Free Path, Minimum Conductivity and Anderson Physical Review Letters, 106, 046803 (2011) N. Leconte, D. Soriano, S. Roche, P. Ordejon, J.-Ch. Charlier, and J. J. Palacios Magnetism-Dependent Transport Phenomena in Hydrogenated Graphene: From Spin-Splitting to Localization Effects ACS Nano 5, 3987 (2011); DOI: 10.1021/nn200558d A. Cresti, A. López-Bezanilla, P. Ordejón and S. Roche Oxygen surface functionalisation of graphene nanoribbons for transport gap engineering ACS Nano, DOI: 10.1021/nn203573y (2011)

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Carbon fiber tips for scanning probe microscopes and molecular electronics experiments

99 Gabino Rubio-Bollinger1, Andres Castellanos-Gomez1,2, Stefan Bilan3, Linda A. Zotti3, Carlos R. Arroyo1, Nicolás Agraït1,4, Juan Carlos Cuevas3 1

Departamento de Física de la Materia Condensada (C–III). Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid, Spain. 2 Kavli Institute of Nanoscience, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands. 3 Departamento de Física Teórica de la Materia Condensada (C–III). Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain. 4 Instituto Madrileño de Estudios Avanzados en Nanociencia IMDEA-Nanociencia, E-28049 Madrid, Spain. gabino.rubio@uam.es Introduction The tip is certainly one of the most important components of a scanning probe microscope because it is the one directly interacting with the surface under study. We have developed carbon fiber tips which optimize the performance of combined scanning tunneling and atomic force microscopes (STM/AFM). The remarkable electrical and mechanical properties of carbon fiber make these tips more suitable for combined and/or simultaneous STM and AFM than conventional metallic tips. For instance, carbon fiber tips are shown lightweight, rigid and much more robust against accidental tip crashes than metallic tips. Moreover, we have fond that tunnel currents of up to 100 pA can be obtained while in the attractive force regime, that is, in the non-contact regime. This indicates that the carbon fiber tip apex remains clean and oxide-free even under room conditions. Additionally, we have demonstrated the suitability of these carbon-based tips as contact electrodes to form single molecule junctions. Conductance vs. stretching traces, measured on gold/octanethiol/carbon tip junctions, show well defined plateaus at 5.9 × 10-6 G0, which we attribute to be the conductance value for a single octanethiol molecule. This ensures that carbon tips provide a proper mechanical linking to molecules with a methyl ending group allowing to routinely form single-molecule bridges. Experimental Although in STM the use of mechanically fabricated tips (by simply cutting a metallic wire) is rather common, the AFM resolution strongly depends on the tip sharpness because of the presence of long range interactions between the tip and the sample. In this work we have thus developed an electrochemical procedure to etch carbon fiber tips [1]. A 5-10 mm long fiber is extracted from the fiber rope. One end of the fiber is immersed a few microns into a drop of 4M KOH solution suspended in a 4 mm inner diameter gold ring . A voltage bias difference of 5-6 Volts is applied between the unimmersed fiber end and the gold ring which is grounded. The etching takes place over a period of tens of seconds until the fiber breaks, opening the electrical circuit and stopping the etching. Afterwards the fiber is rinsed with distilled water. Reproducible tips with sub-100 nm apex radius can be obtained following this procedure as shown in figure 1.

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Several traces of conductance as a function of tip retraction distance G(z) are shown in Fig. 2(a). The conductance traces show plateaus at specific values which are the signature of the formation of molecular junctions [2]. The conductance plateaus do not always occur at the same conductance values because of variations in the microscopic details of the molecule arrangement between the electrodes. To overcome junction-to-junction fluctuations we have performed a statistical analysis in which all junction realizations, without selecting conductance traces, are represented as a histogram (Fig. 2(b)). We follow the procedure described in ref. [3] to remove the background tunneling contribution from the histogram in order to better resolve its structure. We find that there are two Gaussian peaks whose centers are located at G1 = (5.9 ± 4.1) × 10-6 G0 and G2 = (1.3 ± 0.5) × 10-5 G0. The presence of multiple peaks in the histogram in previous STM break junction experiments on molecular junctions has been attributed to a varying number of molecules contributing to the transport [2]. References [1] [2] [3]

A. Castellanos-Gomez, N. Agrait, and G. Rubio-Bollinger, Nanotechnology 21, (2010), 145702. B. Xu, and N. J. Tao, Science 301, (2003) 1221. J. L. Xia, I. Diez-Perez, and N. J. Tao, Nano Lett. 8, (2008) 1960.

Figures

Figure 1: Scanning electron micrograph of a carbon fibre tip electrochemically etched following the procedure described above. The curvature radius of the tip apex is estimated to be 55 nm.

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Figure 2: (a) Conductance traces (shifted horizontally by 0.5 nm for clarity) showing characteristic conductance plateaus. Below a conductance of 1.5 × 10-6 G0 the measurements are limited by the noise level of the current amplifier. (b) Conductance histogram built from 740 traces (dark blue) and corrected histogram (light blue) after subtracting the tunnelling contribution.

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Nano-patterning of fluorinated graphene by electron beam

101 Saverio Russo1, F. Whiters1, T. Bointon1, M.Dubois2, M.F. Craciun1

1 Centre for Graphene Science, University of Exeter, Exeter, United Kingdom Clermont Universite’, UBP, Laboratoire des Mate’riaux Inorganiques, Aubie’re, France

s.russo@exeter.ac.uk Transparent organic electronics holds great promise for future applications, for example in smart windows and in photovoltaic cells. The development of transparent organic electronics is reliant on achieving high conductivity materials with a gate tuneable carrier mobility and low contact resistance at the interface with metals. Graphene –a layer of carbon atoms in a honeycomb lattice- offers just such a possibility. Chemically functionalized graphene with hydrogen [1] and fluorine [2, 3] induce the opening of a band gap in the otherwise zero–gap semimetallic graphene. The ability to tune, by functionalization, the conductivity of graphene over the full range from insulator to metal opens the possibility of accessing a conceptually new scenario of transparent graphene based electronic circuits. Here we demonstrate that fluorinated graphene –a wide gap semiconductor with sp3 electron orbital hybridization- can be selectively reduced to sp2 graphene by electron-beam irradiation [4], see Figure. We employ this functionality to pattern conductive nanostructures in a sheet of fluorinated graphene, realizing transparent graphene-based electronic devices such as nanoribbons without the need for etching of graphene. Electrical transport experiments over a wide range of temperatures (ranging from room temperature to 4K) of the ribbons show a transport gap whose size is inversely proportional to the width of the patterned ribbons. In this gap, electrons are localized, and charge transport is dominated by variable range hopping. Charging effects constitute a significant portion of the activation energy, and we find that the activation energy scales well with the width of the ribbons [4]. References [1] [2] [3] [4]

D.C. Elias, Science 323, 610 (2009). F. Withers et al., Phys. Rev. B 82, 073403 (2010); F. Whiters et al., Nanoscale Research Letters 6, 526 (2011) F. Whiters et al., Nano Letters 11, 3912 (2011)

Figures

Figure 1: Left. Illustration of the defluorination process assisted by electron irradiation. Right. Measured sample resistance per square plotted against the electron irradiation dose. The sample displays an insulator to metal transition.

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New approaches in obtaining nano- and microstructured metal oxide materials with improved properties and functionality Aigi Salundi, Martin Järvekülg, Martin Timusk, Tanel Tätte, Valter Reedo, Madis Paalo, Kristjan Saal and Ants Lõhmus Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia aigi.salundi@ut.ee Sol-gel has emerged as an alternative to conventional methods of preparing oxide materials. Sol-gel technology has many advantages. For example there is no need to use high temperatures during syntheses process. The rise of nanotechnology stimulated new trends in sol-gel which holds considerable potential with its simplicity and possibility of giving the precursor different shapes before gelation- oxide material that is generally hard to process is synthesized directly in desired shape. This work reports our recent progress in the elaboration of novel original sol-gel materials [1], [2], [3]. The preparation and characterization of sol-gel micropatterns, -rolls and, -tubes and functional composites is covered. Firstly, a novel method for preparation of aminofunctional SiO2 films has been developed. The latter method allows varying the concentration of amino groups on the surface and wettability of the film. Prepared materials were successfully used as substrates in DNA microarray analyses and found to be suitable for practical applications including mutation screening. Simple pulling methods for preparing metal oxide fibers with diameters 200 nm- 50 nm have been developed. Also, sharp oxide tips can be obtained by pinching the pulled sol jets. Tip radius of the transparent and electrically conductive SnO2 tip depends on fiber drawing speed, ambient humidity and viscosity of the precursor. Tip radii down to 15-25 nm were achieved. The sharp structures were tested as probes in STM and tunneling current induced photon imaging, both showed very good lateral resolution. Similar high-viscosity sol is also suitable for micro molding with polymeric stamps; surface structures of ~ 1 micron lateral dimension could be thereby readily obtained. Sol-gel method is also suitable for preparing electrodes from CNT-doped high refractive index transparent metal oxides like TiO2 or SnO2. After baking at 340°C in air, dense oxide ceramics containing aligned nanotubes were obtained as fibers and films. Prepared materials were conductive (up to 500 S/m). By that we have shown that CNT-doping can boost the electrical properties of the material without sacrificing transparency. Another composite material that we have elaborated is glass dispersed liquid crystal (GDLC), transparency of which can be controlled by electric field [4]. Microdroplets of liquid crystal in modified SiO2 matrix are obtained by phase separation, prepared GDLC devices show superior performance compared to these reported in papers by other groups. Our finest transparency difference which we have achived is 74 %. Also, we have recently introduced a strategy for obtaining novel microscopic tubular oxide structures by film rolling. This non-template synthesis includes the steps of gelling the surface of a metal-alkoxide precursor, spontaneous cracking of obtained gel film, subsequent dissolving of the non-gelled layer of precursor and self-rolling of the gel film segments. It is important to point out that the gel film rolling is based on general and spontaneous phenomena. Formation of a gel film can be observed in all situations where a sol layer with a suitably low flowing rate is exposed to humidity. This method can potentially yield tubular structures of tunable size from all sol-gel materials. Advantages of novel obtained microtubular structure of oxide material include large specific surface area and outstanding resistance to high temperatures and harsh chemical environment for using them in catalytic processes. For the first time cracking prosess of metal alkoxide sol-gel films have been modeled [3].

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References

104

[1]

[2]

[3]

[4]

Hussainov, M., Tätte, T., Paalo, M., Gurauskis, J., Mändar, H., Lõhmus, A., Structure and Rheological Behavior of Alkoxide-Based Precursors for Drawing of Metal Oxide Micro- and Nanofibres. Advanced Materials Research, 214 (2011), 354 - 358. Saal, K., Tätte, T., Järvekülg, M., Reedo, V., Lõhmus, A., Kink, I., Micro- and nanoscale structures by sol-gel processing, International Journal of Materials and Product Technology, 40(1/2) (2011), 2 - 14. Jõgi, J., Järvekülg, M., Kalda, J., Salundi, A., Reedo, V., Lõhmus, A., Simulation of cracking of metal alkoxide gel film formed on viscous precursor layer using a spring-block model, EPL - A Letters Journal Exploring the Frontiers of Physics, 95(6) (2011), 64005-p1 - 64005-p6. Timusk, M., Järvekülg, M., Lõhmus, R., Kink, I., Saal, K., Sol–gel matrix dispersed liquid crystal composite: Influence of methyltriethoxysilane precursor and solvent concentration, Materials Science and Engineering B, 172(1) (2010), 1 - 5.

Figures

Figure 1: Tubular oxide structures, which combines sol-gel method and self-formation.

← Figure 2: CNT doped metal oxide electrodes

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Nanobiochemical applications of rolled-up nanomembranes for: From Nanorobotics to Lab-in-a-tube systems S. Sánchez, A.A. Solovev, W. Xi, S. M. Harazim and O.G. Schmidt Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany s.sanchez@ifw-dresden.de We will present the recent progress on the fabrication of rolled-up 3D microstructures for nanobiochemical applications, in particular (i) the development of catalytic microjet engines, and (ii) a new bioanalytic microsystem platform, dubbed “Lab-in-a-tube”, for single cell studies. The fabrication of autonomous nanomachines which could one day navigate inside the human body remains a challenging dream in nanotechnology and biomedicine [1]. Over the last few years, there has been increasing interest in the use of chemistry to propel tiny engines in a similar fashion that nature uses biochemistry to power biological motors. [2,3] There are three main challenges that researchers try to conquer when engineering artificial nanomachines: i) efficient self-propulsion; ii) motion control; iii) the development of useful task such as the transport of cargo in fluid, biosensing and bioseparations in chips. Rolled-up microtubes [4] containing a Pt catalyst [5] or catalase enzymes [6] in their inner layer can trigger the breakdown of the hydrogen peroxide fuel wherein they are immersed. The hollow structure generates a thrust of oxygen microbubbles in their interior released from one of the tubular openings which in turn propels the microtubes. Here we will present our recent advances on the controllable manipulation of microjets in microfluidic channels [7] and the transport of different microobjects [8] and biological material such as cells [9] (Figure 1). We performed different methods to wirelessly control the motion and the power of the microjets. [8,10] In addition, there is a great interest in reducing the toxicity of the fuel used to self-propel artificial nanomachines. Therefore, a method to increase the efficiency on the conversion of chemical into mechanical energy is desired. We employed temperature control to increase the efficiency of the microjet engines while simultaneously reducing the amount of the peroxide fuel. Cytoxicity tests proved the viability of Fibroblast cells in the working solution for about 1 hour. [11] We will also present the scalability of these nanotubular machines down to sub-micron size in diameter (we obtained the World Guinness Record  for the Smallest man-made jet engine) [12] which can be used as nanotools. Based on the novel “Lab-in-a-tube” concept, [13] we can design arrays of multifunctional devices for the observation of single cell behavior inside transparent microtubes that can be employed for diverse biological applications (Figure 2). [14] A simple approach to guide the outgrowth of neurons [15] and yeast cells [16] in mi-crotubular confined spaces has been previously reported which paved the way to more advanced studies based on biocompatible microtubular structures such as mitosis time, spindle reorientation and mechanical and chemical stress to mammalian cells. [17] Microtubular structures act both as microreactor chamber for cellular growth and also as optical sensors for studying different phenomena occurring within the cells confined in their interior. The multifunctionality of the “Lab-in-a-tube” platform will be further extended by integrating different modules into a single microtubular unit, bringing up several applications such as optofluidics sensors [18], magnetic biodetection [19] among others.

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References

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[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19]

T.E. Mallouk and A. Sen, Sci. Am., 300 (2009) 72; G. A. Ozin, et al, Adv. Mater. 17, (2005) 3011. T. Mirkovic, et al, Small 6,(2010) 159; M. Pumera, Nanoscale 2 (2010) 1643; W. Paxton, et al, Angew. Chem. Int. Ed., 45, (2006) 5420; S. Sanchez, M. Pumera, Chem. As-J. 4 (2009) 1402. O.G. Schmidt and K. Eberl, Nature, 410, (2001) 168; Y. F. Mei et al, Adv. Mater. 20, (2008) 4085; Y. F. Mei, et al., Chem. Soc. Rev. 40, (2011) 2109. A. A. Solovev et al, Small, 5, (2009) 1688. S. Sanchez et al, J. Am. Chem. Soc., 132, (2010) 13144. S. Sanchez et al, J. Am. Chem. Soc., 133, (2011) 701. A. Solovev et al, Adv. Funct. Mater. 20, (2010) 2430. S. Sanchez et al. Chem. Commun., 47, (2011) 698. A. A. Solovev et al Angew. Chem. Int. Ed.,DOI: 10.1002/anie.201102096 (2011) S. Sanchez et al. J. Am. Chem.Soc. 133, (2011) 14860 http://www.guinnessworldrecords.com/Search/Details/Smallest-jet-engine/74227.htm E. J. Smith et al NanoLett 11, (2011) 4037 S. M. Harazim et al. (2011) Submitted. S. Schulze et al, Adv. Eng. Mat 12, (2011) B558 G. S. Huang et al, Lab Chip. 9 (2009) 263 W. Xi et al. In preparation. G.S. Huang et al, ACS Nano 4, (2010) 3123 I. Moench et al, ACS Nano 5, (2011) 7436

Figures

Figure 1: Controlled manipulation and transport (A-C) of CAD cells by using catalytic microbots. The motion of the microbot is aligned by an external magnetic field (schematic insets) provided by a small magnet placed underneath the sample containing the cells and microbots. D) SEM image of Ti/Fe/Pt rolled-up microtubes with CAD cells.

Figure 2: Array of Fibronectin functionalized SiO/SiO2 microtubes containing dyed HeLa cells. The cells interact with the biocompatible microtubes and they can go inside where they even proliferate.

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Higher-order resonances in single-arm nanoantennas: Evidence of Fano-like interference

107 F. López-Tejeira, R. Paniagua-Domínguez, R. Rodríguez-Oliveros, J. A. Sánchez-Gil Instituto de Estructura de la Materia (IEM-CSIC), Consejo Superior de Investigaciones Científicas Serrano 121, 28006 Madrid, Spain j.sanchez@csic.es Experimental and theoretical investigations have shown that metallic nanorods act as standing-wave resonators for localized plasmon resonances in the optical regime [1,2], thus exhibiting geometrical halfwavelength resonances with spectral positions depending mainly on the length of the rods. This particular type of so-called “optical nanoantennas” have raised the prospect of significant improvements in fields such as photodetection [3], field-enhanced spectroscopy [2,4], or control of emission direction in single-molecule light sources [5]. Generally speaking, most of device-oriented studies are focused on nanoantennas operating at the dipole-like resonance. However, structures with a high aspect ratio may support additional resonances that have usually been the subject of a more fundamental research work. Hence, several authors have already elucidated the scaling properties of high-order longitudinal modes, as well as their dependence on shape, size, orientation and dielectric environment by means of diverse approaches and techniques. Nevertheless, a relevant issue has yet to be addressed for multi-resonant nanoantennas, that is the emergence of asymmetric, line profiles in single particle extinction or scattering spectra. Interestingly, such a feature seems to go unnoticed for the nanoplasmonics community, despite being apparent in some previous reports. In this work [6], we show that these asymmetric line profiles can be easily understood in terms of the socalled Fano-like interference between localized plasmon resonances that has been recently reported for a variety of coupled metal nanoparticles [7,8]. Being more precise, we present a simplified analytical model that describes spectral features of a single-arm nanoantenna in terms of Fano-like interference. Contrary to the common assumption that interference does not play any role in total scattering or extinction of a single metallic surface, we find a good agreement with numerical results, which are attained through the separation of variables (SVM) [9], finite element (FEM) [10], and surface integral equation (SIEM) methods [11,12]. In Figure 1 we present the calculated scattering efficiency Qsca for a single silver spheroid surrounded by glass (εd= 2.25) under the assumption that incident field is p-polarized and impinges perpendicular to the long side of the rod. Different curves correspond to increasing values of total length L within the [100,400] nm range, whereas the polar diameter D is set to 30 nm for all calculations. As can be seen, the position of resonances increases linearly within the L range. For L/D>5, the peaks arising from resonances with n=1 and n=3 are clearly apparent, as it is the asymmetry of the line shape between them. This suggests the interaction of adjacent resonances to be compatible with a Fanolike interference model [6], where the lower resonance plays the role of continuum in canonical Fano line shape [7]. This is in turn numerically revealed for a variety of single-arm nanoantennas, namely: • Nanospheroids, • Nanorods, • Nanowires.

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Furthermore, we make use of explicit analytical expressions for light scattering by spheroids to conclude that not only spectral but also spatial overlap (i.e. non-orthogonality) between interacting modes underlies the emergence of such single-rod resonances [6]. The research presented in this paper is supported by the Spanish “Ministerio de Ciencia e Innovación” (projects Consolider-Ingenio EMET CSD2008-00066 and NANOPLAS FIS2009-11264) and the “Comunidad de Madrid” (MICROSERES network S2009/TIC-1476). R. Paniagua-Domínguez acknowledges support from CSIC through a JAE-Pre grant.

References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

Mühlschlegel, P.; Eisler, H.-J.; Martin, O. J. F.; Hecht, B.; Pohl, D.W., Science 308 (2005) 1607. Muskens, O. L.; Giannini, V.; Sanchez-Gil, J. A.; Gómez Rivas, J., Nano Lett. 7 (2007) 2871. Knight, M. W.; Sobhani, H.; Nordlander, P.; Halas, N. J., Science 332 (2011) 702. Ming, T.; Zhao, L.; Yang, Z.; Chen, H.; Sun, L.; Wang, J.; Yan, C., Nano Lett. 9 (2009) 3896. Taminiau, T. H.; Stefani, F. D.; Segerink, F. B.; van Hulst, N. F., Nat. Photonics 2 (2008) 234. López-Tejeira, F.; Paniagua-Domínguez, R.; Rodríguez-Oliveros, R.; Sánchez-Gil, J. A., to be published. Miroshnichenko, A.; Flach, S.; Kivshar, Y. Rev. Mod. Phys. 82 (2010) 2257. Luk’yanchuk, B.; Zheludev, N. I.; Maier, S. A.; Halas, N. J.; Nordlander, P.; Giessen, H.; Chong, C. T., Nat. Mater. 9 (2010) 707. Voshchinnikov, N. V.; Farafonov, V. G., Astrophys. Space Sci. 204 (1993) 19. COMSOL Multiphysics finite element software, version 4.2: RF module. Giannini, V.; Sánchez-Gil, J. A., J. Opt. Soc. Am. A 24 (2007) 2822. Rodríguez-Oliveros, R.; Sánchez-Gil, J. A., Opt. Express 19 (2011) 12208.

Figures

Figure 1: Calculated scattering efficiency as a function of wavelength for a single Ag spheroid (top right) surrounded by glass (εd = 2:25). Incident field is p-polarized and impinges perpendicular to the rotation axis of the spheroid. Different curves correspond to increasing values of L, whereas D is set to 30 nm for all calculations. Right: Nanorod geometries for which evidence is found of Fano-like interference [6]

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Application of graphene to transistors: CVD growth, nanoribbon formation, and electrical properties Shintaro Sato and Naoki Yokoyama Green Nanoelectronics Research Center (GNC), AIST 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan shintaro.sato@aist.go.jp Graphene, a two-dimensional honeycomb carbon lattice, has excellent electronic, thermal, and mechanical properties. It is therefore considered to be a promising material for future electronics devices. In fact, our final goal is to use graphene as a transistor channel for future large scale integrated circuits (LSIs). In order to realize it, however, there are still many issues to address. One of them is to synthesize graphene uniformly all over a large substrate. Another issue is to form a bandgap in graphene, which is essential for obtaining a high on/off ratio in graphene transistors. Optimizing the structure of a graphene transistor, which includes the choice of electrode and insulator materials, is also an important issue. Furthermore, we have to develop a good fabrication process for graphene transistors. In this presentation, we mainly address the first two issues above. First, we demonstrate graphene growth over a 200-mm wafer by chemical vapor deposition (CVD) [1, 2]. We then describe self-organizing formation of graphene nanoribbons (GNRs) on steps of a Cu surface [3]. We also explain our recent results on patterning of GNRs by Helium Ion Microscope (HeIM) and the on-off operation of a GNR transistor thus fabricated [4]. Graphene was grown on a Cu film deposited on a SiO2/Si wafer using C2H4 or CH4 diluted by Ar/H2 as the source gas. The total gas pressure was typically kept at 1 kPa. The typical growth temperature was 860Â°C. The thickness of Cu films was 500 nm or 1000 nm. The substrate was first annealed for 20 min in Ar/H2 mixture (10:1), and hydrocarbon was then added for growth. The growth time and the partial pressure of the hydrocarbon were changed to optimize the growth condition. The synthesized graphene was characterized by scanning electron microscopy (SEM), transmission electron spectroscopy (TEM), and Raman spectroscopy. Figure 1(a) shows a 200-mm Cu/SiO2/Si wafer on which graphene was grown [1, 2]. In this case, the partial pressure of C2H4 was 0.59 Pa and growth time was 4 min. Raman spectra taken at 5 different positions on the wafer are shown in Fig. 1(b). The Raman spectra suggest that graphene was uniformly grown all over the wafer. Figure 1(c) shows a cross sectional TEM image taken around the center of the wafer, showing graphene formation. A bright-filed TEM image and the corresponding selected area electron diffraction (SAED) pattern are shown in Fig. 1(d) and (e), respectively. It can be seen that three sets of diffraction patterns, which are very close to each other, exist. SEM results (not shown) show that the grain size of this graphene sample is estimated at ~1 Îźm. Therefore, this result suggests that graphene grains are almost in the same direction. We also investigated how the size of graphene grains depended on the growth conditions and found that the size increased with decreasing the partial pressure of C2H4, as discussed in ref. 5. However, we also obtained results suggesting that the grain size and direction were affected by the surface morphology of Cu. Incidentally, when the total pressure was low (~100 Pa) with CH4 as the source gas, we often observed preferential graphene growth on steps of Cu substrate, as shown in Fig. 1(f) [3]. The existence of high-index surfaces at steps is considered to be a reason for this preferential formation. We also made GNRs by direct etching of graphene with HeIM [4]. For this purpose, single layer graphene flakes were mechanically exfoliated from HOPG using adhesive tape, and then deposited on a silicon wafer with a 300-nm-thick thermal oxide layer. On the obtained graphene flakes, source (S)

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and drain (D) electrodes were made by electron-beam lithography, followed by Ti/Au (5/30 nm) depositon and lift-off. A GNR with 5 nm width and 50 nm length was then patterned by irradiation of He ion beams as shown in Fig. 2(a). Here, source and drain regions are separated by the dark region where graphene was removed by He ion etching. A GNR was formed in the middle of this dark region, as highlighted by a broken circle. A schematic of the GNR device is shown in Fig. 2(b). Figure 2(c) represents the back gate bias dependence of the drain current at different drain biases at T = 45 K. The drain current is strongly suppressed between -10 V and 0 V. Most of the spike-like peaks are reproduced by multiple measurements, suggesting that these peaks reflect the resonant conduction through localizing states characteristic to each GNR. The on-off ratio at Vd = 1 mV is estimated at about two orders of magnitude. This ratio decreases as the drain bias increases, and almost disappears when Vd > 200 mV. The back gate bias range, ΔVg, that corresponds to the transport gap, is estimated at about 10 V. From this value, the transoprt gap enrgy scale is evaluated to be ~200 meV [6]. To our knowledge, this is the first on-off operation of a GNR transisor fabricated with HeIM. This work was suported by the Japan Society for the Promotion of Science (JSPS) through the “Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program),” initiated by the Council for Science and Technology Policy (CSTP). This work was partly conducted at the AIST Nano-Processing Facility supported by Innovation Center for Advanced Nanodevices (ICAN), National Institute of Advanced Industrial Science and technology (AIST), Japan. References [1] [2] [3] [4] [5] [6]

S. Sato, et al. ECS Trans. 35(3) (2011) 219. S. Sato, et al. ECS Trans. 37(1) (2011) 121. K. Hayashi, et al. Extended Abstracts of 72th JSAP Fall Meeting 2011, Yamagata (2011) 2a-ZF-9. S. Nakaharai, et al., Extended Abstracts of the 2011 SSDM, Nagoya (2011) 1300. X. Li, et al. Nano Lett. 10 (2010) 4328. M. Han, et al. Phys. Rev. Lett. 104 (2010) 056801.

Figures

Figure 1: (a) Graphene synthesized on a Cu film deposited on a 200-mm Si/SiO2 wafer. (b) Raman spectra of graphene at positions of A-E shown in (a). (c) A cross sectional TEM image of the graphene around the center of the wafer. (d) Bright field image of graphene on a TEM grid. (e) Selected area diffraction pattern obtained from a circular area of graphene partially shown in (a). (f) GNRs grown on steps on Cu.

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Figure 2: (a) Helium ion micrograph of a GNR with a schematic illustration. Graphene was removed in the dark region between the source (S) and drain (D). (b) A schematic of the GNR device. (c) Back gate bias (VBG) dependence of drain current (Id) at different drain biases (Vd) at T = 45 K.

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Simulation of nano-scale magnetic systems

111 Thomas Schrefl1.2, Simon Bance1, Markus Gusenbauer1, Gino Hrkac2, Ivan Cimrak3, Josef Fidler4, Dieter Suess4 1

St. Pรถlten University of Applied Sciences, Matthias Corvinus Str. 15, St. Pรถlten, Austria The University of Sheffield, Department of Materials Science and Engineering, Sheffield, UK 3 Dep. Soft. Techn., Faculty of Management Science and Informatics, University of Zilina, Slovakia 4 Vienna University of Technology, Wiedner Haupstr. 8-10, Vienna, Austria 2

thomas.schrefl@fhstp.ac.at Nanoscale magnetism is the key technology in a growing field of applications ranging from magnetic data storage to biomedical application. The design of materials and devices heavily relies on modeling and simulation: (1) Ideas based on intuition or theory can be tested. (2) Devices can be substantially improved by optimization. (3) Virtual design based on computer models reduces the costs. In this talk we will give two examples. One from magnetic data storage and one in cancer therapy. Common to both examples is that traditional finite element simulation for magnetization dynamics is combined with other modern simulation techniques. The underlying concept is the continuum theory of micromagnetism which describes magnetization processes at a length scale ranging from the nanometer scale to several micrometers. The micromagnetic equations describe the magnetization as function of time and space. Optimization tools for bit patterned recording Finite element based numerical optimization can help to design nano-magnet devices ranging from storage to sensor and to microwave generators. As an example we will show its application for minimizing the write error rate in magnetic data storage. In magnetic data storage the magnetic units that store single bits reach dimensions below 10 x 10 nm2. The time to write a single bit is a fraction of a nano-second. Bit patterned magnetic recording, where each bit is stored on a single magnetic island that is predefined on a substrate require a precise engineering of the magnetic elements. The timing and the spatial distribution of the write field has to be optimized so that it the target bit is addressed and successfully written. Numerical optimization techniques are applied to design the optimal head and media structure, so that the bit error rate is minimized [1]. The solution of the micromagnetic equations for the key components of a hard disk give a detailed account of how bits are written onto the magnetic islands. The driving force is the magnetic field created by the current through the coils. This field changes the magnetization in the write head which in turn creates the write field that switches the bits on the data layer. A hybrid/finite element boundary element method is applied for the computation of the interaction between the writer and the data layer. The write field profile can be optimized by changing the shape of the pole tip and the shield geometry. Figure 1 shows the simulation cycle. The writer geometry is parameterized. For a given set of parameters the finite element mesh is generated, the recording process is simulated and an objective function is evaluated. A optimization tool based on a response surface method suggests a new set of geometrical parameters, which describe the pole tip and the shield geometry. These parameters are feed into the mesher for the next step of the optimization cycle. Design of mircofluidic chips for biomedical applications In the field of biomedicine magnetic beads are used for drug delivery and to treat hyperthermia. If the surface of the beads a functionalized with antibodies magnetic beads can be used for immunomagnetic cell capturing and cell sorting. Alternatively, magnetic beads can be used to create well defined structures in a microfluidic chip. If formed by magnetic beads, microposts arrays are tunable:

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The size, the position, and the shape of the nano-posts can be controlled by an external magnetic field [2]. By changing the distance between the chains it is possbile to switch from immuno-magnetic cell capture to mechanical filtering during in-situ operation of the microfluidic device. On application of microfluidic chip is the isolation of circulating tumor cells from peripheral blood [3]. The proposed tunable chip combines affinity capture and size capture of circulating tumor cells in a single, flexible device. We simulate the arrangement of magnetic beads into nano-post arrays using micromagnetics, discrete particle dynamics and fluid dynamics. The balance between the magnetic force and the drag force leads to the formation of nano-chains as shown in Figure 2. Once the structure has been formed, the Lattice-Boltzmann method with immersed elastic cell models is used, in order to simulate the interaction of cells with the nano-posts. Simulations give design guidelines such as the optimal gap size between the nano-posts for high yield cell enrichment. The authors acknowledge the financial support by the Life Science Krems GmbH. References [1] [2] [3]

M. A. Bashir, T. Schrefl, J. Dean, A. Goncharov, G. Hrkac, D. A. Allwood, D. Suess, Journal of Magnetism and Magnetic Materials, 324 (2012) 269. M. Gusenbauer, A. Kovacs, F. Reichel, L. Exl, S. Bance, H. Ă&#x2013;zelt, T. Schrefl, Journal of Magnetism and Magnetic Materials, doi:10.1016/j.jmmm.2011.09.034 S. Nagrath, L. V. Sequist LV, S. Maheswaran, D. W. Bell, D. Irimia, L. Ulkus, M. R. Smith, E. L. Kwak, S. Digumarthy, A. Muzikansky, P. Ryan, U. J. Balis, R. G. Tompkins, D. A. Haber, M. Toner,Nature 450 (2007) 1235.

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Figure 1: Numerical optimization of the head geometry and media properties for ultra-high density magnetic recording. Finite element micromagnetics together with a global optimization tool provide design guidelines that reduces the bit error rate.

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Figure 2: Simulation of magnetic bead arrangement and cell flow in microfluidic chips. Left: Microfluidic chip based on a grid of self-organized magnetic beads. Red blood cells are flexible enough to pass the gap between the nano-posts. Right: Circulating tumor cells are larger and stiffer than blood cells and get trapped in the magnetic bead array.

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Thermo-responsive smart materials

113 Peter Schurtenberger Physical Chemistry, Lund University, Lund, Sweden While materials and nanoscience is currently still conducted within traditional areas that focus on “solid state”, “soft matter” or biological systems, the development of the functional hybrid materials of the future requires a much more integrated, cross-disciplinary approach. Particularly promising routes towards novel materials and devices follow a soft nanotechnology approach, where bioinspired fabrication strategies based on so-called bottom-up rather than top-down processes are used to assemble various nanoscaled building blocks into two- and three-dimensional materials and devices. In the soft nanotechnology approach to nanomaterials, the fabrication of structures is thus based on self-assembly without human intervention, where the instructions for assembly emerge from the intermolecular interactions between the synthons. However, traditional self-assembled materials based on colloids, block copolymers and surfactants suffer from the fact that the structures that emerge from a simple free energy minimization are often polydisperse and irregular. Quite in contrast, nature has excelled in making highly monodisperse, regular structures through the controlled self-assembly of biological molecules such as virus capsid proteins. It is clear that the design and fabrication of future materials and devices for photonics, molecular electronics, or drug delivery would enormously benefit if we were capable of selfassembling synthetic nanostructures with the precision and reliability found in biological selfassembly. However, this requires control over their assembly into precise and predictable structures, which still remains the primary obstacle to the bottom-up construction of novel materials and devices. It can only be achieved if we understand the relationship between specific types of interactions and the resulting target structures, and subsequently develop the capability to engineer and control these interactions between the different building blocks. Progress in soft matter based materials science and nanotechnology thus critically depends on a sound understanding of the various intermolecular interactions acting in often highly complex systems. I will show how we can create functional hybrid materials using self-assembly processes. I will in particular focus on the possibilities offered by responsive nanoparticles. Responsive nanoparticles such as thermo- or pH-sensitive microgels or magnetic hybrid particles allow for a variation of the form, strength and range of the interaction potential almost at will. They are not only attractive models in basic research, but also of considerable technological importance to materials science and nanotechnology as building blocks for nanostructured responsive organic-inorganic hybrid systems. The combination of nanoscale inorganic moieties with organic polymers allows us to create materials with enhanced or even completely new properties. I will demonstrate how we can design and synthesize functionalized responsive nanoparticles that can be used to make adaptive polymer-colloid nanomaterials with tailored optical, magnetic and mechanical properties. An important aspect of soft nanotechnology is the multi-scale characterization required by these hierarchical hybrid materials, where we have to determine not only the structure of and interactions between the nanoparticle building blocks, but also the resulting mesoscale structures and their optical, mechanical and magnetic properties. I will thus also introduce our experimental toolbox that combines real and reciprocal space techniques covering up to 8 orders in length scales, starting from almost atomic resolution.

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References

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[1] [2] [3]

Sรกnchez-Ferrer, M. Reufer, R. Mezzenga, P. Schurtenberger and H. Dietsch, Nanotechnology 21, 185603 (2010) M. Hammond, H. Dietsch, O. Pravaz, and P. Schurtenberger, Macromolecules 43, 8340 (2010) H. Dietsch, V. Malik, M. Reufer, C. Dagallier, A. Shalkevich, M. Saric, T. Gibaud, F. Cardinaux, F. Scheffold, A. Stradner, and P. Schurtenberger, Chimia 62, 805 (2008)

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Figure 1: A soft nano approach to mimicking nature. Shown are biological examples of self-assembled materials such as viruses, lens fiber cells, opal or tubules as well as artificial analogues discussed in the presentation.

Figure 2: Combining responsive particles as building blocks with tuneable interaction forces and a multi-scale characterization platform to make and characterize hybrid structures and their materials properties.

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In-Situ CCVD Growth of Hexagonal Carbon for CMOS-Compatible Nanoelectronics: From Nanotube Field-Effect Devices to Graphene Transistors Udo Schwalke, Pia Juliane Wessely, Frank Wessely, Emrah Birinci, Martin Keyn, Lorraine Rispal Technische Universität Darmstadt, Schlossgartenstrasse 8, 64289 Darmstadt, Germany schwalke@iht.tu-darmstadt.de In this work, the in-situ growth of carbon nanotubes (CNTs) and graphene films directly on oxidized silicon wafers by means of catalytic chemical vapor deposition (CCVD) is demonstrated. In-situ means that the carbon structures are directly grown in their final position for device applications (cf. Figs. 1a and 2, respectively) so that tedious transfer and alignment procedures are obsolete. Our CMOS compatible fabrication process for carbon nanotube field-effect transistors (CNTFETs) allows large scale production of good quality devices at low cost and within a short time. To achieve this, a dedicated in-situ growth method for single-walled nanotubes (SWNTs) has been developed, based on the catalytic chemical vapor deposition (CCVD) of carbon from methane. The major novelty of the process consists in the introduction of a sacrificial catalyst (i.e. well-optimized Ni/Al bilayer), which is evaporated on the whole wafer surface (see Fig. 1a), catalyzes the growth of 1 nm diameter SWNTs (see Fig. 1 c and d) and simultaneously transforms itself into an insulator (aluminum oxide covered with nickel nanoclusters) during the growth process at elevated temperatures (800 - 900 °C), so that there is no need to structure the catalyst after deposition. Only a single optical lithography step is needed to structure Pd source/drain contact regions for electrical characterization, allowing the simultaneous fabrication of approximately 1,000 transistors on one two-inch wafer even with non-optimized layout. Details on the self-aligned fabrication process have been reported previously [1, 2]. The suitability for mass fabrication of this process has been verified on more than 15,000 devices. Extended yield statistics on 700 devices have been performed, leading to the result of 41% of fully functional high on/off-current ratio devices, i.e. typical > 107 (see Fig. 1e) within all measured devices (see Fig. 1f). On the basis of a modified in-situ CCVD growth process, first successful attempts of growing mono-, biand few-layer graphene films directly on oxidized Si-wafers have been performed (Fig. 2). In contrast to CNT growth, the aluminum only partially transforms into aluminum-oxide (AlxOy) [3]. Accordingly, the structured catalyst can be directly used as source and drain contacts for device characterization as illustrated in Fig. 2. Using the in-situ CCVD process several hundred graphene devices are realized simultaneously across one 2’’ wafer and are directly functional after the CCVD growth. These graphene devices possess a well defined channel length in the range of 1.6 μm to 5 μm while the channel width varies randomly from approximately 0.1 μm to several microns, depending on local growth conditions.The in-situ grown graphene layers extend only a few microns on the SiO2 surface and therefore do not always fill up the maximum designed channel width. The number of grown stacked graphene layers depends on the adjusted process parameters, e.g. temperature and gas mixture and have been confirmed by AFM step-height measurements and TEM analysis [4]. In addition, Raman spectroscopy has been performed within the channel region in between the catalytic areas. The Raman data shown in Fig. 3 confirm the existence of few-layer graphene growth (Fig. 3a), most likely 5 layers, rather than e.g. amorphous carbon deposition during CCVD. Additional analysis of the shape and position of peaks G and D’ indicate strong interactions of graphene with underlying SiO2. These intensive interactions between graphene and SiO2 are characteristic for our CCVD process due to the in-situ growth at high temperatures. Fig. 4 shows the transfer characteristic of a monolayer graphene field-effect device. The Dirac-point at VG=-6V confirms the co-existence of

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electron and hole conduction as expected for graphene [5]. However, a slightly unsymmetrical current-voltage characteristic is noted in Fig. 4. Obviously, hole-conduction is preferred in our in-situ CCVD grown graphene, which appears typical for CVD-grown graphene according to Hall-effect measurements reported from other groups [6]. In conclusion, this successful demonstration of the in-situ catalytic growth of semiconducting CNTs and graphene layers provides a novel technological basis for integrated silicon-CMOS compatible carbon nanoelectronics. Acknowledgements This research is part of the ELOGRAPH project and funded within the ESF EuroGRAPHENE EUROCORES programme. References [1] [2] [3] [4] [5] [6]

L. Rispal and U. Schwalke, IEEE Electron Device Lett., 29, (2008) 1349-1352,. L. Rispal, T. Tschischke, H. Yang, and U. Schwalke, ECS Trans., 13, (2008) 65. P.J. Ginsel, F. Wessely, E. Birinci, U. Schwalke, “CVD Assisted Fabrication of Graphene Layers for Field Effect Device Fabrication” IEEE DTIS, (2011) Athens, Greece L. Rispal, P.J. Ginsel, U. Schwalke, ECS Transactions, 33 (2010) 13-19. F. Schwierz, “Graphene transistors“ Nature Nanotechnology, 5 (2010) W. Wua et al, Sensors and Actuators B 150 (2010) 296–300

Figures

Figure 2: Schematic drawing of in-situ grown graphene layer produced by means of CCVD using a nickel-aluminum catalyst.

Figure 3: (a) Raman spectrum of graphene (few-layer) measured within the channel region. (b) Raman spectrum measured in approximately 5μm distance to the channel region.

Figure 1: a: Schematic of CNTFET. b: Example of processed wafer with approx. 1000devices. c and d: AFM measurements (topographical scan and cross-sections) of in-situ grown CNTs showing their uniformity. e: Example of transfer characteristic of high quality CNTFET with on/off-current ratio of > 107. f: Distribution of high quality devices within ～700 nanotube devices

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Figure 4: Current-voltage characteristics of insitu grown monolayer graphene. The Dirac point shows the conductivity of electrons and holes as well.

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Graphene Spintronics

117 P. Seneor1, B. Dlubak1, M.-B. Martin1, A. Anane1, C. Deranlot1, B. Servet2, S. Xavier2, R. Mattana1, H. Jaffrès1, M. Sprinkle3, C. Berger3,4, W. de Heer3, F. Petroff1, A. Fert1 1

Unité Mixte de Physique CNRS/Thales, Palaiseau and Université Paris-Sud, Orsay, France , 2 Thales Research and Technology, Palaiseau, France 3 School of Physics, Georgia Institute of Technology, Atlanta, USA 4 Institut Néel, CNRS, Grenoble, France pierre.seneor@thalesgroup.com

Spintronics is a paradigm focusing on spin as the information vector. Ranging from quantum information to zero-power non-volatile magnetism, the spin information can be also translated from electronics to optics. Several spintronics devices (logic gates, spin FET, etc) are based on spin transport in a lateral channel between spin polarized contacts. We want to discuss, with experiments in support, the potential of graphene for the transport of spin currents over long distances in such types of device. The advantage of graphene over classical semiconductors and metals comes from the combination of its large electron velocity with the long spin lifetime due to the small spin-orbit coupling of carbon. This leads to spin diffusion lengths ≈ 100 µm and above. We will present new magneto-transport experiments on epitaxial graphene multilayers on SiC [1] connected to cobalt electrodes through alumina tunnel barriers [2]. The spin signals are in the MΩ range in terms of ∆R = ∆V/I [3]. This is well above the spin resistance of the graphene channel. The analysis of the results in the frame of drift/diffusion equations [4] leads to spin diffusion length in graphene in the 100 µm range for a series of samples having different lengths and different tunnel resistances. The high spin transport efficiency of graphene can also be acknowledged up to 75% in our devices [3]. The advantage of graphene is not only the long spin diffusion length. The large electron velocity also leads to short enough dwell times even for spin injection through tunnel barriers. Our results on graphene can be compared with previous results [5] obtained on carbon nanotubes. In conclusion, graphene, with its unique combination of long spin life times and large electron velocity, resulting in long spin diffusion length, turns out as a material of choice for large scale logic circuits and the transport/processing of spin information. Understanding the mechanism of the spin relaxation, improving the spin diffusion length and also testing various concepts of spin gate are the next challenges. References [1]

[2] [3] [4] [5]

W.A. de Heer, C. Berger, X. Wu, M. Sprinkle, Y. Hu, M. Ruan, J.A. Stroscio, P.N. First, R. Haddon, B. Piot, C. Faugeras, M. Potemski, and J.-S. Moon, Journal of Physics D: Applied Physics, 43, 374007, 2010. B. Dlubak, P. Seneor, A. Anane, C. Barraud, C. Deranlot, D. Deneuve, B. Servet, R. Mattana, F. Petroff, and A. Fert, Appl. Phys. Lett. 97, 092502 (2010) B. Dlubak, P. Seneor, A. Anane, M.-B. Martin, C. Deranlot, B. Servet, S. Xavier, R. Mattana, M. Sprinkle, C. Berger, W. A. De Heer, F. Petroff, and A. Fert, Submitted H. Jaffrès, J.-M. George, and A. Fert, Physical Review B, 82, 140408(R), 2010. L.E. Hueso, J.M. Pruneda, V. Ferrari, G. Burnell, J.P. Valdes-Herrera, B.D. Simons, P.B. Littlewood, E. Artacho, A. Fert, and N.D. Mathur, Nature, 445, 410, 2007.

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Nanosmile website on nanosafety Training, Education and Public dialogue issues

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Y. Sicard UJF-CEA, F. Tardif CEA Liten 17, rue des Martyrs, F 38054 Grenoble cedex 9, France, yves.sicard@cea.fr francois.tardif@cea.fr http://www.nanosmile.org The nanoparticles are finding new industrial applications every day in fields as various as electronics, biomedicine, pharmaceutics, cosmetology, chemical catalysis, new materials, and others. We are about to witness the advent of a new era in the industrial history of nanoparticles. New types of nanoparticles that up to now were under laboratory development are on the brink of massproduction. Economists are now speaking about the dawn of a new industry for the 21st century that could rank with the automobile and microelectronics industries in terms of turnover. Nevertheless, this new industry will only be dynamically developed if two critical conditions are met. First, the safety issues have to be settled for the entire life cycle of the nano products: from fabrication to the end of life through usage. Second but not least, nanotechnologies have to be accepted by the public at large. Hence, important work, both scientific and technical has to be performed to reduce so far as we can the risks induced for humans as well as for the environment by the fabrication and use of nanomaterials. This requires on one hand an evaluation of the hazards of nanoparticles (nanotoxicology, thermal behaviour), and on the other hand, techniques that bring exposure under control. In parallel to this technical work, there is a need for accompanying educational and communication actions. First, in order to maintain the exposure levels in workshops and laboratories As Low As Reasonably Achievable (ALARA), it is of prime importance to educate the future potentially exposed workers and their associated management. Second, it is necessary to fuel the societal debate, and inform the public at large about the potential risks, but also the potential advantages, of the nanomaterials. The way that risk issues are addressed has dramatically evolved over the past twenty years. Regarding regulated risks such as emerging risks [1], scientists and engineers nowadays are required to consult the Society before deciding on a risk management strategy. During years they produced innovations without consulting the Society, whereas today responsible innovation should take the public concern into account. As indicated on Fig. 1, governance of an emerging risk [2, 3] involves a complex interaction between different types of actions:

More or less long term effect actions as Risk assessment and Life Cycle Analysis researches in order to define hazard and exposure knowledge for production, use and recycling phases, â&#x2C6;&#x2019; Then follow actions as the definition of regulations and socio-economic analysis of the risk-benefit balance [4], â&#x2C6;&#x2019; Dealing with uncertainties, implementation of very short term effect actions is required: such as applying the precautionary principle by limiting exposure to potentially dangerous engineered nanoparticles and nano-objects. â&#x2C6;&#x2019; Short and middle term effect actions such as interactive information and public dialog have to be considered in order to reconcile diverging interests e.g. employee vs. employer, consumer vs. producer, citizen vs. politic vs. industrial interest. Figure 1: Emerging risk governance framework

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Consequently, in 2006, in addition to the technical work performed at the CEA in the frame of the European project NanoSafe2, the authors designed an interactive website structured on three levels of knowledge: − DISCOVER for consumers, NGOs and the general public in order to facilitate the nanomaterials potential risks understanding and contribute to public dialogue. − EXPLORE for students, scientists and everyone who wants to know more. − KNOW HOW for scientists and industrials and people who want to check the precaution supposed to be taken.

Figure 2: Nanosmile concept http://www.nanosmile.org

This website, initially implemented as an e-learning support available internally at the CEA, has been gradually opened to the public at large and updated in the frame of EU FP7 iNTeg-Risk, NanEX [5], NanoHOUSE [6] and NanoCode [7]. This communication will succinctly present: − The emerging risk governance context − What can we expect from Risk Communication Science? [7], [8], [9], [10], [11] − Nanosmile design, implementation, feedback and perspectives − The methodological and the didactical options chosen to set up the NanoSmile website should finally discussed. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

As defined by EU-OSHA (2005), OECD (2003), ETPIS (2007) International Risk Governance Council (IRGC) http://www.irgc.org/ FP7 iNTegRisk Project http://www.integrisk.eu-vri.eu/ ECHA Guidance Fact Sheet http://guidance.echa.europa.eu/index_fr.htm NanEX Project FP7 http://www.nanex-project.eu NanoHOUSE Project FP7 http://www-nanohouse.cea.fr NanoCode Project FP7 http://www.nanocode.eu Dan Kahan & David Rejeski, Project emerging on nanotechnologies (March 2009) Chris.Tourney, Nature Nanotechnology, Vol 4, (March 2009) Mateo Bonazzi, European Commission, Communicating nanotechnology, (March 2010) David Berube, White paper, communicating risk in the 21st century, NNCO, (Feb 2010)

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Nucleic-acid based molecular structures, devices and circuits

121 Friedrich Simmel Physics Department, TU München The highly predictable base-pairing interactions between sequence-complementary DNA (or RNA) molecules have already been utilized for the construction of a large variety of molecular structures and devices. Most spectacularly, the recently developed DNA origami technique facilitates the molecular assembly of two- and even three-dimensional nanoscale objects with almost arbitrary shape -and with nanometric precision. In this talk, some of our recent work on DNA nanoconstruction will be presented, in particular the utilization of super-resolution microscopy methods for the characterization of DNA nanoassemblies [1,2], and the arrangement of nanoparticles along such DNA scaffolds. In addition to the realization of static molecular nanostructures one of the goals of molecular nanotechnology is the creation of dynamic molecular assemblies that resemble naturally occurring molecular machines. DNA and RNA molecules have already been utilized for the construction of a variety of molecular devices that can be switched between several distinct mechanical states, that generate nano-scale motion or that bind and release molecules on demand [3]. Even more, DNA recognition reactions have also been employed for the realization of artificial regulatory circuits, which can be used to control the timing of molecular assembly processes, and to direct the operation of nucleic acid-based nanodevices. As an example for this, an artificial RNA-based reaction “circuit” will be demonstrated that generates oscillating RNA concentrations in vitro. The oscillations can be utilized to control the motion of the well-known DNA “tweezers” system, or to clock the production of functional RNA molecules [4]. An important aspect of the generation of larger and more complex molecular circuit is the “back-action” that is exerted by increasing molecular load on the overall systems behavior. This issue will be also discussed in the context of the oscillator/tweezers system. References [1] [2] [3] [4]

C. Steinhauer, et al. Angew. Chem. Int. Ed. 48, 8870 (2009). R. Jungmann, et al. Nano Lett 10, 4756 (2010). Y. Krishnan, et al. Angew. Chem. Int. Ed. 50, 3124 (2011). E. Franco, et al. Proc Natl Acad Sci U S A 108, E784 (2011).

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Surface Stress-induced Domain Dynamics and Phase Transitions in Epitaxially Grown VO2 Nanowires Jung Inn Sohn, †,⊥ Heung Jin Joo,†,‡ Keun Soo Kim, § Hyoung Woo Yang,§ A-Rang Jang,§ Docheon Ahn,|| Hyun Hwi Lee,|| SeungNam Cha,⊥ Dae Joon Kang, § Jong Min Kim,⊥ Mark E. Welland† ⊥

Frontier Research Laboratory, Samsung Advanced Institute of Technology, Yongin, Gyeonggi, 446712, Republic of Korea † Nanoscience Centre, University of Cambridge, Cambridge CB3 0FF, United Kingdom ‡ Semiconductor Research and Development Centre, Samsung Electronics Co., Yongin, Republic of Korea § BK21 Physics Research Division, Department of Energy Science, Institute of Basic Sciences, SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746, Republic of Korea || Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea junginn.sohn@samsung.com; djkang@skku.edu We demonstrate that surface stresses in epitaxially grown VO2 nanowires (NWs) have a strong effect on the appearance and stability of intermediate insulating M2 phases, as well as the spatial distribution of insulating and metallic domains during structural phase transitions. During the transition from an insulating M1 phase to a metallic R phase, the coexistence of insulating M1 and M2 phases with the absence of a metallic R phase was observed at atmospheric pressure (See Fgiure 1). In addition, we show that for a VO2 NW without the presence of an epitaxial interface, surface stresses dominantly lead to spatially inhomogeneous phase transitions between insulating and metallic phases. In contrast, for a VO2 NW with the presence of an epitaxial interface, the strong epitaxial interface interaction leads to additional stresses resulting in uniformly alternating insulating and metallic domains along the NW length. In order to demonstrate the detailed structural changes and coexistence of two different insulating phases (M1, M2), we prepared naturally bent NWs with uniform local curvature and non-clamped (strain-free interface) on a c-cut sapphire substrate using a PDMS transfer method, which is a technique widely used for transferring graphene. Raman measurements were carried out at two featured positions; i) the non-clamped, straight part of a NW (A in the upper inset of Figure 4a), and ii) the largest bent part of a NW with the high tensile strain at the centre of the outer edge of the local curvature region (B in the lower inset of Figure 2a). As shown in Figure 2a, the evolution of Raman spectra obtained from the straight region of a NW (A), which exhibits direct structural changes from M1 to M2 phases, is quite similar to that measured on a transferred NW non-clamped shown in Figure 1. Interestingly, in the bent part of a NW (B), coexistence of both M1 and M2 phases as evidenced by peaks associated with only M1 and M2 phases were observed even at room temperature. As the temperature increases, the intensity of M1 peaks gradually decreases and that of M2 peaks continuously increases, showing the evolution of M1-M2 phases. When the temperature increases further, R phases start to appear. References [1] [2] [3]

Morin, F. J. Phys. Rev. Lett. 1959, 3, 34-36. Sohn, J. I.; Joo, H. J.; Porter, A. E.; Choi, C.–J.; Kim, K.; Kang, D. J.; Welland, M. E. Nano Lett. 2007, 7, 1570-1574. Sohn, J. I.; Joo, H. J.; Ahn, D.; Lee, H. L.; Porter, A. E.; Kim, K.; Kang, D. J.; Welland, M. E, Nano Lett. 2009, 9, 3392-3397.

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Figure 1: Temperature dependence of Raman spectra of transferred individual VO2 NWs. As the temperature increases, phonon frequencies shift toward higher frequencies and phase transitions from an M1 to an R phase occur spatially along the NW length. Raman spectra indicated by A, B and C were obtained from the circle region of the NWs, respectively (left inset). Optical images of bright and dark domain patterns corresponding to insulating and metallic phases, respectively (right inset), reveal spatial phase transitions along the NW length.

Figure 2: (a) Raman spectra obtained from the straight part (A in the upper inset) and bent part (B in the lower inset) of a VO2 NW, which show the direct evolution of M1-M2 phases. (b) Temperature dependence of XRD data from ensembles of epitaxially grown VO2 NWs, measured during cooling from 303 K to 6 K. These results demonstrate that M1 and M2 phases can coexist with the absence of an R phase at atmospheric pressure.

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A nanoscience-based approach to protein condensation diseases

125 Anna Stradner Department of Chemistry, University of Fribourg, Chemin du MusĂŠe 9, CH-1700 Fribourg, Switzerland anna.stradner@fkem1.lu.se ; anna.stradner@unifr.ch Understanding interparticle interactions in protein solutions is of central importance to gain insight into the origin of protein condensation diseases such as Creutzfeldt Jakob, Alzheimer, Parkinson or cataract, the leading cause of blindness worldwide[1]. Here I will demonstrate how we can use a nanoparticle-based approach to understanding protein stability and aggregation/phase separation. I will discuss in particular the system eye lens and show that the eye lens proteins (alpha-, beta- and gamma-crystallin) are ideally suited for an attempt to use well-defined analogies to nanoparticles in suspension in order to understand the molecular origins of cataract formation [2]. The approach that we follow in our work is schematically shown in Figure 1. I will present results from a study of the structural and dynamic properties of individual lens protein solutions and mixtures up to concentrations corresponding to those found in the eye lens using smallangle neutron (SANS) and X-ray scattering (SAXS) combined with light scattering, rheological measurements, molecular dynamics simulations and statistical physics [3-5]. We discuss the results in the context of simple models from colloid science and demonstrate that they indeed allow us to interpret the complex protein phase diagrams. The nanoparticle-based approach and an example for the results thus obtained are shown in Figure 2 I will show that a subtle balance of interactions between the individual proteins controls transparency of lens protein mixtures at high concentrations, comparable to those in the living eye lens. In particular I will demonstrate that the stability of lens protein mixtures is greatly enhanced by weak, short-range attractions between two of the prevalent mammalian crystallins, alpha- and gammacrystallin. Provided they are not too strong, such mutual attractions considerably decrease the critical temperature and the related opacity due to light scattering in the vicinity of the critical point, and are thus essential for lens transparency.

References [1] [2] [3] [4] [5]

Benedek G.B. Invest. Ophthalmol. Vis. Sci. 1997,38, 1911. Stradner A.,et al.J. Phys.: Cond. Mat. 2005, 17, S2805-S2816 Stradner A et al. Phys. Rev. Lett. 2007, 99, 198103 Dorsaz N., et al. J. Phys. Chem. B 2009, 113, 1693 Dorsaz N. et al. Soft Matter 2011, 7, 1763

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Figure 1: The soft nanotechnology approach to cataract formation or why nanoscience tools can help to understand lens transparency and its loss: in our approach we start with welldefined and well-characterized building blocks, the eye lens proteins, which we model as nanoparticles interacting via an effective pair interaction potential. Based on a sound understanding of their interactions, phase behaviour and microstructure we then try to understand the properties of the resulting bionanomaterial, namely the eye lens.

Figure 2: A) Schematic representation of the coarse-grained view of a protein, where the exact three dimensional structure of a protein is replaced with a globular particle that then interacts with other proteins via an effective pair potential. B) SANS data obtained with a concentrated γ-α-crystallin mixture together with the theoretical prediction for either a hard sphere repulsion (dashed line) or a weak mutual attraction (red solid line) between γ- and α-crystallins (see [3] for details).

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Application of sol-jets in preparation of different shape metal oxide materials

127 Tanel T채tte1, Marko Part1, Keijo Riikj채rv1, Medhat Hussainov1, Kelli Hanschmidt1, Ioannis Chasiotis2, Valter Kiisk1, Kaupo Kukli1, Aile Tamm1, Vadim Kessler3, Ants L천hmus1 1 Institute of Physics, University of Tartu, Riia 142, 51014, Tartu, Estonia Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL-61801, USA 3 Uppsala BioCenter SLU, Dept. of chemistry, Box 7015, Arrheniusplan 8 750 07, Uppsala, Sweden 2

tanelt@fi.ut.ee Sol-gel technology is based on science of nanocolloidal suspensions known as sols. When the purpose is to prepare metal oxide materials in a controlled manner, the corresponding metal alkoxides are the primary choice as precursor compounds. During the last decade, the majority of researches have started to agree that chemistry behind the transformation of metal alkoxides to oxides is different compared to the chemistry of widely used Si-alkoxides that undergo hydrolysis and polymerization processes after reaction with water. When set into contact with water, metal alkoxides directly form oxide nanoparticles as a result of one step chemical process [1]. Therefore, by adding certain amount of water and controlling the parameters like concentration, acidity, temperature etc., it is possible to obtain metal oxide nanocolloidal systems, suitable for sol-gel processing. High surface energy of nanoparticles should naturally lead to their dissolution or coagulation inside the liquid phase. To achieve stability of sols, stabilising layer is used on the surface of particles. In the case of alkoxides, the stabilizing role is played by monolayer of alkoxy groups on the surface of particles. The stabilising effect of the layer depends largely on its thickness, the length and shape of alkoxy groups have high impact on the properties of sols and their gelation. Probably for the first time, we have shown that at least in the case of SnO2 alkoxy sols, the alkoxy groups can be fully exchanged by -OH groups. In the consequence, it is possible to get highly pure and fully stable colloids that are based just on SnO2 in water. Such liquid systems provide clear cassiterite structure and could be concentrated up to 20-30 %. When more water is removed, these sols transform into gels being perfect materials for sol-gel processing. In the current presentation we will demonstrate the application of jeting in order to shape the precursor sols and produce metal oxide particles with desired geometries [Fig. 1]. Micro- and nanofibres could be obtained when stable slender jets are solidified [2]. Micro- and nanospheres, capsules and torroids could be obtained when the jets are broken into pieces and the droplets formed solidify under specific conditions. Nanometrically sharp needles could be obtained when jets are pulled into air until break-up. Immediate solidification of break-points is possible due to the high speed of reaction between alkoxide precursors and water [3]. Microtubes could be obtained when losses in volume occurs during the solidification of the jets. Crucial in geting the tubes is that the process starts by formation of rigid shell on the surface of the jet. All obtained structures can be post-treated by aging and baking to achieve fully dense nanocrystalline oxide materials. When the residual organics is removed from the matter and the size of crystallites is still kept low enough then the eventually formed materials will possess optical transparency, being potentially applicable as waveguides for micro- and nanophotonic devices and sensors [4]. We have shown that microtubes, when made of yttria stabilized zirconia (YSZ), could be used as high temperature ion-conducting membranes. Potential of such tubes could be realized in construction of high temperature (up to 1000 째C) and high pressure (at least 1000 atm.) microfluidic systems and as

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miniature plasma chambers. Applications of the materials are supported by their high Young modulus, that remains within 100-200 GPa range, while tensile strenght is around 1GPa, being comparable to that of stainless steel. To realise the applications of the materials we have also started studies on atomic layer deposition (ALD) of functional films, such as TiO2, MgO, Ta2O5, on the surface of materials formed by sol-gel. ALD is inherently a chemical deposition method driven and controlled by the adsorption capability of chemically active surface. ALD of oxides is based on the sequential adsorption and reaction cycles between metal and oxygen precursors, with only one submonomolecular material layer deposited in a single cycle. For instance, MgO films can be deposited layer-by-layer from magnesium beta-diketonate and ozone [5]. Due to the surface control and the self-limitation of the adsorption process, dense and ultrathin films can be deposited over complexshaped, three-dimensional, substrates, including micro- and nanostructures created by sol-gel. In this way optical, electrical, mechanical and chemical properties of nanofibres, microtubes, nanoparticles, etc., can be modified. References [1]

[2]

[3] [4]

[5]

Vadim G. Kessler and Gulaim A. Seisenbaeva, New Insight into Mechanisms of Sol-Gel Process and New Materials and Opportunities for Bioencapsula-tion and Biodelivery, NATO Science for Peace and Security Series C: Environmental Security, (book title: Sol-Gel Methods for Materials Processing), 2008, 139-153, Springer. Tanel Tätte, Medhat Hussainov, Madis Paalo, Marko Part, Rasmus Talviste, Valter Kiisk, Hugo Mändar, Kaija Põhako, Tõnis Pehk, Kaido Reivelt, Marco Natali, Jonas Gurauskis, Ants Lõhmus and Uno Mäeorg, Science and Technology of Advanced Materials, 12 (2011) 034412. Tanel Tätte, Madis Paalo, Vambola Kisand, Valter Reedo, Alexander Kartushinsky, Kristjan Saal, Uno Mäeorg, Ants Lõhmus and Ilmar Kink, Nanotechnology, 18(2) (2007) 125301. Limin Tong and Eric Mazur, Nanophotonics and Nanofibres, Handbook for Fiber Optic Data Communications: A Practical Guide to Optical Networking, Ed. Casimer DeCusatis, (2008) 713728, Academic Press, Burlington, MA. Matti Putkonen, Leena-Sisko Johansson, Eero Rauhala and Lauri Niinistö, Surface-controlled growth of magnesium oxide thin films by atomic layer epitaxy, Journal of Materials Chemistry, 9 (1999) 2449.

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Figure 1: Different shape metal oxide materials that can be prepared from sol-jets.

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Aptamer-based scaffolds for developments in nanotechnology

129 Jean-Jacques Toulmé, Laurence Delaurière, Laetitia Evadé*, Emilie Daguerre*, Sonia Da Rocha*, Eric Dausse, Laurent Azéma and Carmelo Di Primo. ARNA Laboratory, Inserm U869, University of Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux, France *Novaptech, 2 rue Robert Escarpit, 33607 Pessac, France. jean-jacques.toulme @inserm.fr Aptamers are oligonucleotides identified in large randomly synthesized libraries containing up to 1015 different oligomers, through in vitro selection, a process known as SELEX (Systematic Evolution of Ligands by EXponantial enrichment). Aptamers have been successfully raised against a wide range of targets: amino acids, nucleic acid bases, proteins, intact viruses and live cells. These molecules display generally a high affinity for their target, characterized by Kds in the nanomolar range for macromolecules and in the micromolar range for small molecules. In addition they show a high specificity of recognition and can discriminate between closely related molecules. Aptamer oligonucleotides are easy to synthesize on solid support by phosphoramidite chemistry; they can be easily chemically modified, conjugated to different pendant groups that provide them with new functionnalities or grafted on various surfaces. They presently rival antibodies for many different applications in the field of bio- and nanotechnologies, including for diagnostic or therapeutic applications. We have been working in this area for many years for different purposes (artificial regulation of gene expression, design of probes for imaging or of biosensors) [1]. We recently worked on several aspects that are of interest for aptamer developments in nanotechnology. SELEX is a tedious and repetitive process. The identification and characterization of aptamers may require several months. In order to take full advantage of aptamers it is necessary to implement methodologies that speeds up the selection procedure and increases the throughput of the screening. To this end we assembled a robot that allows the parallel selection of DNA, RNA or chemically-modified oligonucleotides against several targets. Moreover we developped a new screening procedure. Selection is generally followed by cloning and sequencing of the enriched pool of oligonucleotides to enable the bioinformatic comparison of selected sequences. The most represented candidates are then synthesized and their binding properties are individually evaluated thus leading to the identification of aptamers. These post-selection steps are time consuming and introduce a bias to the expense of poorly amplified binders that might be of high affinity and are consequently underrepresented. We described a novel homogeneous solution-based method for screening large populations of oligonucleotide candidates generated from SELEX [2]. This approach, based on the AlphaScreen® technology, is carried out on the exclusive basis of the binding properties of the selected candidates without the needs of performing a priori sequencing. It therefore enables the functional identification of high affinity aptamers. We validated the HAPIscreen (High throughput APtamer Identification screen) methodology using aptamer (R06) targeted to the RNA hairpin (TAR). HAPIscreen can be adapted to any type of tagged target (figure 1) and is fully amenable to automation. Hairpins resulting from intramolecular complementarity between two neighbour regions are recurent RNA motifs. Beyond the biological function of these structures they are also of interest for the construction of scaffolds. Indeed the apical loop at the top of the double-stranded stem is prone to interactions with single RNA regions of another molecule. Using SELEX we identified RNA hairpin aptamer (R06) that recognize a target RNA (TAR) through so-called kissing interactions between complementary loops of both the target and the aptamer. Such a loop-loop complex is characterized

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by a strong binding (Kd = 20 nM) and a very high specificity of recognition. The structure of the complex has been fully characterized by molecular dynamics, X-ray crystallography and NMR [3, 4, 5]. Kissing complexes can be arranged in more complex associations; we demonstrated that dimeric aptamers give rise to extremely stable complexes with a target containing two tandem hairpins [6]. This has been further developed by others for generating 3D scaffolds, taking advantage of the well defined relative geometries of the different helices (stems and loop-loop) [7]. Scaffolds can also be generated by the association of aptamers with organized synthetic polymers (foldamers). We raised aptamers against a cationic octameric oligoamide O2N–(Q+)8–OH which folds into a helix spanning over three turns in the solid state and in solution. This approach proved to be very fruitful. It confirmed from an independent and unbiased assay the prevalence of a specific interaction between multiturn (Q+)n oligomers and G-quadruplex DNA, a motif of increasingly recognized biological relevance. We demonstrated that this interaction can be made completely diastereoselective with one-handed helices. We identified a foldamer that selectively binds to one quadruplex sequence and not to others and identified the first example of a DNA- vs RNA-selective Gquadruplex synthetic ligand [8]. Such a foldaptamer complex can constitute the basis for threedimensional networks which can be further on grafted with various functional groups. Aptamers are of interest for multiple applications; we indeed generated 99Tc-aptamer probes for imaging human brain tumors [9], micro-arrays for detecting viral proteins [10], or targeting nanoparticles for theranostic treatment. The work presented here on aptamer-based nanoscaffolds will extend the potential of these tools. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

Di Primo C, Dausse E and Toulmé JJ, Methods Mol Biol. (2011) 764:279. Dausse E, Taouji S, Evadé L, Di Primo C, Chevet E and Toulmé JJ., J Nanobiotechnology (2011) 9:25. Beaurain, F., Di Primo, C., Toulmé, J.J. and Laguerre, M., Nucleic Acids Res. (2003) 31:4275. Van Melckebeke, H., Devany, M., Di Primo, C., Beaurain, F., Toulmé, J.J., Bryce, D.L. and Boisbouvier, J. Proc Natl Acad Sci U S A (2008) 105:9210. Lebars, I., Legrand, P., Aime, A., Pinaud, N., Fribourg, S. and Di Primo, C. Nucleic Acids Res. (2008) 36:7146. Boucard D, Toulmé JJ and Di Primo C. Biochemistry (2006) 45:1518. Shukla GC, Haque F, Tor Y, Wilhelmsson LM, Toulmé JJ, Isambert H, Guo P, Rossi JJ, Tenenbaum SA, and Shapiro BA., ACS Nano. (2011) 5:3405. Delaurière L., Dong Z., Laxmi-Reddy K., Godde F., Toulmé* J.-J. and Huc* I., submitted. Da Rocha Gomes S., Miguel J., Azéma L., Eimer S., Ries C., Dausse E., Loiseau H., Allard M. and Toulmé J.-J. submitted. Cornet F., Dausse E., Toulmé J.-J.* and Desmecht D.* submitted.

Figures Figure 1: (Left) Scheme of the assay setup using a digoxigenin–tagged aptamer (R06) and a biotinylated target RNA hairpin (TAR). The association of the two components is detected by using both Donor streptavidin (D) and Acceptor anti-digoxigenin (A) coated AlphaScreen® beads. The production of singlet oxygen upon laser excitation by D-phtalocyanin is monitored by the fluorescence emission of A-rubrene beads. (Right) Results obtained when increasing concentrations of dig-R06 were added to A and D beads for different biot-TAR concentrations.

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Interfacial Arrangements with Atomic/Molecular Resolution for Highly Efficient Photoelectrochemical Energy Conversion Kohei Uosaki, 1,2 Katsuaki Ikeda2 International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Japan 2 Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan 1

uosaki.kohei@nims.go.jp Development of the efficient solar energy conversion system is one of the most important global issues in the 21st century. In natural photosynthetic systems, highly efficient conversion of solar energy to chemical energy is achieved based on well ordered arrangement of organic and biological molecules with various functions such as photon absorption, electron relay, and catalyst, i.e., enzyme. Many attempts have been made to realize highly efficient artificial solar energy conversion systems by mimicking natural system but there are still many problems to be solved such as low efficiency and low durability before artificial photosynthesis becomes practical. Here two systems for efficiency enhancement by metal nanoparticles (NPs) and/or metal complexes for photoenergy conversion at metal and semiconductor electrodes modified with molecular layers are described. 1. Plasmonic efficiency enhancement for up-hill photocurrent generation at gold electrode modified with self-assembled monolayer. We have reported highly efficient photoinduced up-hill electron transfer at gold electrode modified with self-assembled monolayer (SAM) of porphyrin-ferrocene coupling thiol molecule as shown in Fig. 1 [1]. Although this system shows very high quantum efficiency, only fraction of solar energy can be utilized because main absorption peak of porphyrin, absorber, is around 420 nm and absorbs not much photons in more high frequency region. Optical antennas, which interface between free-propagating light and localized electromagnetic energy, are indispensable to construct efficient solar-energy conversion system. Since localized electromagnetic fields strongly interact with matter, introduction of optical antennas can increase the population of excited states, leading to high conversion efficiency from photon energy to electric or chemical energy. Surface plasmon polaritons (SPPs), which are collective oscillation modes of free electrons optically excited on a metal surface, are now recognized as a key to manipulate electromagnetic fields on nm scale. When molecules are located near nanostructured metal surface, photon-molecule interactions are greatly enhanced by field localization via excitation of SPPs. One of well-known examples for this concept is surface enhanced Raman scattering (SERS). We have demonstrated that Raman scattering signals from molecular adsorbates are extraordinarily enhanced on nanostructured metal surface [2-7]. Here a metal nano-gap system was introduced as a photon antenna in order to improve the photo-energy conversion efficiency. Theoretical calculation shows that particle plasmon and surface plasmon strongly hybridize in the Au-NP/SAM/Au substrate system. Since such hybridized plasmon is accompanied with extraordinarily enhanced electric field, i.e., photon energy is concentrated in the gap region with the volume of ~nm3, one can expect that various optical events would occur more efficiently in the gap. Figure 2 shows photocurrent action spectra of the porphyrinferrocene SAM measured in 0.1 M NaClO4 electrolyte solution containing 50 mM methyl viologen as an electron acceptor without and with 50 nm Au-NPs on top of the SAM. It is clear that photocurrent was significantly increased by the presence of adsorbed Au-NPs, as expected. The wavelength dependence of the enhancement factor is similar to the calculated extinction spectrum, confirming the enhancement of effective photo-energy conversion efficiency by plasmonic resonances in the nano-gap systems [8]. In the present study, the increased photocurrent is 20-fold of the original value around 660 nm. This result opens up a new possibility for design of photofunctionalized molecular devices with plasmonic photon antennas.

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2. Construction of photoenergy conversion interfaces by molecularly ordered modification of semiconductor surfaces. Hydrogen is the most important clean fuels in the future and production of hydrogen from water by solar energy is required. Photoelectrochemical (PEC) and photocatalytic decomposition of water has been studied for long time. Most serious problem of PEC production of hydrogen from water is that while semiconductor electrodes with small energy gap can absorb large fraction of solar energy but unstable, those with large energy gap are stable but can absorb only small fraction of solar energy. This can be solved by using semiconductor of small gap and separating the reaction site from the surface. We have constructed viologen molecular layer on hydrogen terminated Si(111) surface and then Pt nanoparticle was introduced within the molecular layer by ion-exchange reaction followed by electrochemical reduction. Significant decrease of overpotential for hydrogen evolution reaction (HER) at n-Si electrode was observed by this modification. Further improvement was achieved by constructing multi-viologen-Pt -layers. Viologen acts as molecular wire and Pt acts as HER catalyst. Figure 3 shows photocurrent-voltage relations of hydrogen terminated p-Si(111) electrode and that modified with 1, 3, and 5 viologen-Pt layers. Hydrogen evolution current flowed at more positive potentials than the reversible potential at pSi(111) electrodes modified with multi-viologen (molecular wire)-Pt (HER catalyst)-layers under illumination [9]. In situ XAFS study carried out under operation shows that Pt particles were not formed even when HER took place and the Pt complexes acted as HER catalysts, i.e., confined molecular catalysts, as schematically shown in Fig.4 [10]. The decrease of white line intensity suggests the formation of a hydride complex as an intermediate of HER, although more detailed experimental and theoretical examinations are required to clarify the mechanism. The formation of Pt particles may have been inhibited since the complexes are separated by molecular layers. References: [1] [2] [3] [4] [5] [6] [7] [8] [9]

K. Uosaki, T. Kondo, X.-Q. Zhang, and M. Yanagida, J. Amer. Chem. Soc., 119, 8367 (1997). K. Ikeda, N. Fujimoto, H. Uehara, K. Uosaki, Chem. Phys. Lett. 460, 205 (2008). K. Ikeda, J. Sato, N. Fujimoto, and K. Uosaki, J. Phys. Chem. C, 113, 11816 (2009). U. Jung, M. M端ller, N. Fujimoto, K. Ikeda, K. Uosaki, U. Cornelissen, F. Tuczek, C. Bornholdt, D. Zargarani, R. Herges, and O. Magnussen, J. Coll. Int. Sci., 341, 366 (2010). K. Ikeda, S. Suzuki, and K. Uosaki, Nano Lett., 11, 1716 (2011). K. Ikeda, J. Sato, and K. Uosaki, J. Photochem. Photobio. A: Chemistry, 221, 175 (2011). K. Ikeda, K. Takahashi, T. Masuda, and K. Uosaki, Angew. Chem. Int. Ed., 50, 1280 (2011). T. Masuda, K. Shimazu, and K Uosaki, J. Phys. Chem. C, 112, 29, 10923 (2008). T. Masuda, H. Fukumitsu, S. Takakusagi, W.-J. Chun, T. Kondo, K. Asakura, and K. Uosaki, Adv. Mater., in press, DOI: 10.1002/adma.201102491 (2012).

Figures

Figure 1: Absorption and photocurrent spectra of gold electrode modified with SAM of porphyrin-ferrocene coupling thiol molecule in a solution containing methyl viologen [1].

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Figure 2: Wavelength dependencies of photocurrent and enhancement factor of the porphyrin-ferrocene SAM without and with adsorbed 50 nm Au-NPs measured in 0.1 M NaClO4 solution containing 50 mM methyl viologen [8].

Figure 3: Photocurrentvoltage relations of p-Si(111) electrode modified with various functional layers [9].

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Figure 4: Schematic illustration for electron transfer pathway for HER at Si(111) modified with viologen layer and Pt complex [10].

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Multiscale modelling of nanoscale materials and electronic transport

133 Ivan Kondov(1) & Wolfgang Wenzel(2) Karlsruhe Institute of Technology, (1) Steinbuch Center for Computing and (2) Institute of Nanotechnology, PO Box 3640, D-76021 Karlsruhe, Germany To support accelerating materials development cycles we have developed simulation approaches for de-novo characterization and optimization of materials and device properties with nanoscale constituents. A unified multi-disciplinary approach that integrates materials science simulation and high performance computing is required to transform isolated solutions for specific problems into comprehensive, industry-ready platforms, which are capable of predicting the properties of complex materials on the basis of their constitutive elements. In recent years we have therefore developed simulation methods that describe the conformation and electronic properties of materials built on the basis of well-defined nanoscale constituents. Here we discuss results on single-molecule electronics[1, 2] with application to molecular wires (metallic and organic), on the development of the atomic transistor[3, 4] and organic light emitting diodes[5]. We also discuss the integration of these methods, in close collaboration with colleagues at the CEA into a European framework for multiscale materials modelling in the EU project MMM@HPC. References [1] [2]

[3] [4] [5]

Heurich, J., et al., Electrical transport through single-molecule junctions: From molecular orbitals to conduction channels. Physical Review Letters, 2002. 88(25): p. 256803. Maul, R. and W. Wenzel, Influence of structural disorder and large-scale geometric fluctuations on the coherent transport of metallic junctions and molecular wires. Physical Review B, 2009. 80(4): p. 045424 Xie, F.Q., et al., Independently Switchable Atomic Quantum Transistors by Reversible Contact Reconstruction. Nano Letters, 2008. 8(12): p. 4493-4497. Xie, F., et al., Multilevel Atomic-Scale Transistors Based on Metallic Quantum Point Contacts. Advanced Materials, 2010. 22(18): p. 2033-2036. Kwiatkowski, J.J., et al., Simulating charge transport in tris(8-hydroxyquinoline) aluminium (Alq3). Physical Chemistry Chemical Physics, 2008. 10(14): p. 1852-1858.

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Effect of magnetoelastic anisotropy on domain wall dynamics in amorphous microwires

135 A. Zhukov1,2, J.M. Blanco3, M. Ipatov1, V. Zhukova1 1 Dpto. de Física de Materiales, Fac. Químicas, UPV/EHU, 20018, San Sebastián, Spain 2 IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain 3 Dpto. de Física Aplicada EUPDS, Universidad del País Vasco, 20018 San Sebastián, Spain arkadi.joukov@ehu.es Recently studies of current and magnetic field driven domain walls (DW) propagation in thin magnetic wires (planar and cylindrical) attracted considerable attention [1-3] owing to possibility of application of DW propagation for data storage and logics (magnetic random memory MRAM devices, logic devices)[1]. Quite fast DW propagation of single domain wall at relatively low magnetic field has been reported for cylindrical glass coated amorphous microwires with positive magnetostriction constant with typical diameters of ferromagnetic nucleus about 10-20 µm[3,4]. Glass-coated ferromagnetic wires exhibit a number of unusual and interesting magnetic properties such as magnetic bistability and giant magneto-impedance, GMI, effect [3,5,6]. Magnetic bistability, observed previously in few amorphous materials, is related with single and large Barkhausen jump [3,5,7]. From the point of view of DW dynamics studies, amorphous glass-coated microwires with positive magnetostriction constant are unique materials allowing studies of single domain wall dymaics in a cylindrical micrometric wire. The magnetization process in axial direction runs through the depinning and subsequent propagation of the single closure domain, although the micromagnetic origin of rapidly moving head-to head DW in microwires is still [8]. It is worth mentioning, that the preparation of glass-coated microwires involves simultaneous solidification of composite microwire consisting of ferromagnetic metallic nucleus inside the glass coating introducing in this way considerable residual stresses inside the ferromagnetic metallic nucleus and glass coating and induce additional magnetoelastic anisotropy [5]. But until now little attention has been paid to studies of the influence of magnetoelastic anisotropy on DW dynamics in microwires [9]. Therefore in this paper we studied the effect of magnetoelastic anisotropy on DW propagation in family of amorphous magnetically Fe-Co based bistable microwires with different magnetostriction constant, λs, varying from λs≈ 10-7 to λs≈35 x10-6. The magnetostriction constant, λs, in system (CoxFe1-6 -6 x)75Si15B10 changes with x from -5x10 at x= 1, to λs≈35 x10 at x≈0.2[10]. Within each composition of metallic nucleus we also produced microwires with different ratio of metallic nucleus diameter and total diameter, D, i.e. with different ratios ρ=d/D. This allowed us to control residual stresses, since the strength of internal stresses is determined by ratio ρ [5]. The experimental set-up is described elsewhere [4,9].The magnetoelastic energy, Kme, is given by Kme ≈ 3/2 λsσ,

(1)

where σ =σi + σa – total stress, σi –are the internal stresses, σa – applied stresses and λs magnetostriction constant [5,8]. In this way we studied the effect of magnetoelastic contribution on DW dynamics controlling the magnetostriction constant, applied and/or residual stresses. Usually it is assumed that domain wall (DW) propagates along the wire with a velocity, v: v=S(H-H0)

(2)

where S is the DW mobility, H is the axial magnetic field and H0 is the critical propagation field. Dependences of domain wall velocity, v, on magnetic field, H for Fe16Co60Si13B11 and Co41.7Fe36.4Si10.1B11.8 amorphous microwires with the same ρ-ratio are shown in Fig.1. In this case, the

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effect of only magnetostriction constant is that higher magnetostriction constant (in according to ref. [10] for Co41.7Fe36.4Si10.1B11 microwire λs≈ 30x10-6 should be considered, while for Fe16Co60Si13B11 composition λs≈ 15x10-6) results in smaller DW velocity at the same magnetic field and smaller DW mobility, S. In order to evaluate the effect of ρ-ratio, i.e. effect of residual stresses on DW dynamics, we performed measurements of v(H) dependences in the microwires with the same composition, but with different ρ–ratios. Dependences of DW velocity on applied field for Co41.7Fe36.4Si10.1B11.8 microwires with different ratios are shown on Fig.2. Like in Fig.1, at the same values of applied field, H, the domain wall velocity is higher for microwires with higher ρ-ratio, i.e. when the internal stresses are lower [5]. We also measured v(H) dependences for one of already measured in Fig.3 Co41.7Fe36.4Si10.1B11.8 microwires (ρ ≈ 0,55) under applied stresses (see Fig. 3). Considerable decreasing of domain wall velocity, v, at the same magnetic field value, H, have been observed under application of applies stress. Additionally, increasing of applied stress, σa, results in decreasing of DW velocity. Consequently, from observed experimental dependences we can conclude, that the magnetoelastic energy can affect domain wall mobility, S, what we experimentally observed in few Co-Fe-rich magnetically bistable microwires. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

D.A. Allwood, G. Xiong, C.C. Faulkner, D. Atkinson, D. Petit and R.P. Cowburn, Science 309 (2005) 1688. M. Hayashi, L. Thomas, Ch. Rettner, R. Moriya, X. Jiang, and S. Parkin, Phys.Rev. Lett. 97 (2006) 207205. A. Zhukov, Appl. Phys. Let. vol. 78 (2001) 3106. R. Varga, A. Zhukov, V. Zhukova, J. M. Blanco and J. Gonzalez, Phys. Rev. B 76 (2007)132406. H. Chiriac, T. A. Ovari, and Gh. Pop, Phys. Rev. B, 42 (1995) 10105. M. Vázquez, J.M. García-Beneytez, J.M. García, J.P. Sinnecker and A. Zhukov, J. Appl. Phys. 88, (2000) 6501. A.P. Zhukov, Materials and Design, 5 (1993) 299. P A Ekstrom and A Zhukov, J. Phys. D: Appl. Phys. 43 (2010) 205001. J.M. Blanco, V. Zhukova, M. Ipatov, and A Zhukov, Phys. Status Solidi A 208 (2011) 545. H.Fujimori, K.I.Arai, H.Shirae, H. Saito, T. Masumoto and N.Tsuya, Jap.J. Appl. Phys. 15 (1976) 705.

Figures

Figure 1: v(H) dependences for Fe16Co60Si13B11 and Co41.7Fe36.4Si10.1B11.8 microwires with ρ=0,39.

TNT 2011

Figure 2: v(H) Co41.7Fe36.4Si10.1B11.8 different ratios ρ.

dependences for microwires with

November 21-25, 2011

Figure 3: v(H) dependences for Co41.7Fe36.4Si10.1B11.8 microwires (d≈13,6μm, D≈24,6μm, ρ ≈ 0,55) measured under application of applied stresses, σa.

Tenerife - Spain

Atomistic modeling of multimillion atom nanosystems

137 M. Zieliński Institute of Physics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland Fully ab-initio modeling of multimillion atom nanostructures such as quantum dots in nanowires [1] is still beyond the reach of modern computers. Yet, we show that accurate, atomistic modeling of electronic and optical properties of such systems is possible with the use of empirical tight-binding method for the calculation of single particle states combined with the valence force field simulation of strain fields and the configuration interaction method aiming for description of many-body effects [2,3]. The use of modern massively-parallel computers enables us to calculate excitonic complexes spectra of InAs/GaAs and InAs/InP quantum dots built-into quasi-one-dimensional nanowires, including the details of exciton fine structure [4], understanding of which is a necessary step towards efficient quantum dot based schemes of entangled photon pairs generation [4]. Our approach gives us a predictive capability for determining or tailoring nanosystems that poses demanded electronic or optical properties before actual experiment is performed. References [1] [2] [3] [4]

M. T. Borgstrom, Nano Lett. 5, 1439 (2009) W. Jaskólski, M. Zieliński, G. W. Bryant, and J. Aizpurua, Phys. Rev. B 74, 195339 (2006) M. Zielinski, M. Korkusinski, and P. Hawrylak, Phys. Rev. B 81, 085391 (2010) G. W. Bryant, M. Zieliński, N. Malkova, J. Sims, W. Jaskólski, J. Aizpurua, Phys. Rev. Lett. 105, 067404 (2010)

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November 21-25, 2011

Tenerife - Spain

138

TNT 2011

November 21-25, 2011

Tenerife - Spain

INDEX - POSTERS

TNT 2011

November 21-25, 2011

Tenerife- Spain

TNT 2011

November 21-25, 2011

Tenerife- Spain

(Please, find your final poster number by looking up your name in the Author Index displayed in the Registration and the Poster Exhibition Areas)

Alphabetical Order (92) Presenting Author

Country

Topic

Abdusalyamova Makhsuda

Tajikistan

NanoChemistry

Amato

Czech Republic

Low dimensional materials (nanowires, clusters, quantum dots, etc.)

Filippo

Arias Mediano Jose Luis

Spain

Arias Mediano Jose Luis

Spain

Biedma Ortiz

Rafael

Spain

Buencuerpo

Jeronimo

Spain

Bursikova

Vilma

Czech Republic

Chapartegui

Maialen

Spain

Chashchikhin

Vladimir

Russia

Chen

Xuecheng

Poland

Choi

Seong Soo

Korea

Choi

Seong Soo

Korea

Della Rocca

Maria Luisa France

TNT 2011

Nanomagnetism and Spintronics Nanostructured and nanoparticle based materials Nanostructured and nanoparticle based materials NanoOptics & NanoPhotonics Nanostructured and nanoparticle based materials Nanostructured and nanoparticle based materials

Poster Title Biosorpsion of antimony, nercury and gold at complex conversion of intractable ores Diamond-Like Carbon (DLC) chemical vapor deposition technology: Characterization of DLC nano-layers and Artificial Neural Networks for process modelling Design of Maghemite/Poly(D,L-lactide-coglycolide) Nanoparticles for Magnetic Fluid Hyperthermia Magnetite/Chitosan Nanocomposite for Magnetic Gemcitabine Targeting to Cancer Biodegradable Magnetic Nanomedicine Based on the Antitumor Molecule Tegafur 3D-FDTD Analysis of Absorption Enhancement in Nanostructured Thin Film Solar Cells Plasma deposition of nanocomposite protective coatings on polymer substrates Multifunctional Layers for Safer Aircraft Composites Structures

Molecular design of a sensor for small analyte Theory and modelling at molecules based on a dye adsorbed on silica the nanoscale nanoclusters and nanopores Nanostructured and Template based synthesis of different nanoparticle based mesoporous carbon nanostructures materials Fabrication and Characteristics of Plasmonic Nanobiotechnologies Nanopore on the Pyramid for Ultrafast Genome Sequencing Dynamical Formation of Plasmonic Nanopore Nanobiotechnologies and its Optical Characteristics Graphene / Carbon nanotubes based Single-wall carbon nanotubes quantum dots nanoelectronics and field fabricated by controlled electromigration emission

November 21-25, 2011

Tenerife- Spain

Presenting Author Fernandez Martin

Eduardo

Country Spain

Ferrer-Anglada Núria

Spain

Gaztelumendi

Idoia

Spain

GelinskyWersing

Dagmar

Germany

Gómez

Sacha

Spain

Gómez-Navarro Cristina

Spain

Gong

Singapore

Hao

González Orive Alejandro

Spain

Guslienko

Konstantin Spain

Haberko

Jakub

Switzerland

Hague

James

United Kingdom

Hermosa

Cristina

Spain

Hierro Rodríguez

Aurelio

Spain

Jones

Gavin

Kaasbjerg

Kristen

Denmark

Kalenczuk

Ryszard

Poland

TNT 2011

Topic Nanostructured and nanoparticle based materials Graphene / Carbon nanotubes based nanoelectronics and field emission Nanostructured and nanoparticle based materials

Poster Title Nanostructured GMI multilayers deposited onto flexible substrates for low pressure sensing Flexible Transparent Electrodes Using Carbon Nanotubes Self-Sensing behaviour in glass fiber based epoxy laminates using MWCNT

Nanoporous impedimetric fibre sensor for the detection of acute inflammation in wounds Theory and modelling at On the use of Artificial Neural Networks in the nanoscale Electrostatic Force Microscopy Graphene / Carbon Discriminating chemically derived graphene nanotubes based conductivity through Electrostatic Force nanoelectronics and field Microscopy emission Nanostructured and The study of indium zinc oxide, a material that nanoparticle based can combine with porous silicon to form white materials light emitting diodes Nanostructured and Electrochemical Synthesis and Delivery of nanoparticle based Melanin Covered Gold Nanoparticles and materials Catalytic Activity Thermal relaxation and energy barriers near Nanomagnetism and vortex nucleation field in circular permalloy dot Spintronics arrays NanoOptics & Application of 3D laser nanolithography to the NanoPhotonics fabrication of photonic crystals Graphene / Carbon nanotubes based Tunable graphene bandgaps from superstrate nanoelectronics and field mediated interactions emission Low dimensional materials (nanowires, Highly electrical conductive, ultralarge and clusters, quantum dots, well-ordered MMX nanorods etc.) Tailoring the magnetization states in thickness Nanomagnetism and modulated NdCo5 films with perpendicular Spintronics magnetic anisotropy. Graphene / Carbon nanotubes based Surface Potential Variations in Graphene nanoelectronics and field Induced by Crystalline Ionic Substrates emission Low dimensional materials (nanowires, Phonon-limited mobility in single-layer MoS2 clusters, quantum dots, etc.) Nanostructured and Advances in magnetic silica nanotubes nanoparticle based preparation and characterization materials Nanobiotechnologies

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Kang

Dae Joon

Korea

Karamitaheri

Hossein

Austria

Kiessling

Anja

Germany

Kim

Duckjong

Korea

Kim

Duckjong

Korea

Knotek

Petr

Czech Republic

Kohout

Jaroslav

Czech Republic

Kondov

Ivan

Germany

Kroes

Jaap

Switzerland

Kvashnin

Dmitry

Russia

Lahoz

Fernando

Spain

Langecker

Jens

Czech Republic

Lebar Bajec

Iztok

Slovenia

Lee

Soo-Keun

Korea

Liu

Zunfeng

Netherlands

Maciejewska

Barbara

Poland

Mahmud

Syeda Faria Japan

Manea

Florica

TNT 2011

Romania

Topic

Poster Title

Other

Ferroelectric-gate Field Effect Transistors Based Nonvolatile Memory Devices Using p-type Si Nanowire Conducting Channel

Graphene / Carbon nanotubes based nanoelectronics and field emission Nanostructured and nanoparticle based materials

Transport Gap Engineering in Zigzag Graphene Nanoribbons SiC formation in carbon nanotubes grown from permalloy catalyst particles

Raman characterization of heat spreading in carbon nanotube film Other High power carbon nanotube heater Utilization of Mechanical PropertiesÂ´ Imaging SPM for Detection of Au-nanospheres Used as Biomarkers Nanomagnetism and Effects of surface in epsilon-Fe2O3 Spintronics nanoparticles Theory and modelling at Integrated Services for Multiscale Materials the nanoscale Modelling and Simulation Graphene / Carbon nanotubes based DFT studies of hydrogenated and defective nanoelectronics and field carbon nanotubes emission Graphene / Carbon The strong influence of configurations of nanotubes based graphane islands to electronic properties of nanoelectronics and field graphene/graphane mixing structure emission Time resolved fluorescence characterization of NanoOptics & oligo(p-phenylene ethynylene) based metallic NanoPhotonics nanorods. 9,12-Dithiol-1,2-dicarba-closo-dodecaborane as Other building block for ligands for surfaces, nanoparticles and metal complexes Two-layer synchronized ternary quantum-dot Other cellular automata wire crossings Nanostructured and Carbon Nanoflake/ Tin Oxide Composites Gas nanoparticle based Sensors for NH3 Detection materials Single Walled Carbon Nanotubes as a Scaffold Nanobiotechnologies toConcentrate DNA for Studying DNA-Protein Interactions Nanostructured and Size of the single domain magnetite particles nanoparticle based and MRI parameters materials Development of a new technique for Nanofabrication tools & sharpening of a diamond knife without facet nanoscale integration and ripple formation by low energy Ion beam Nanostructured and Silver-functionalized carbon nanofibers nanoparticle based composite electrodes for Ibuprofen detection materials Other

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Martin-Gondre Ludovic

Spain

Matys

Sabine

Germany

Michalska

Martyna

Poland

Mijowska

Ewa

Poland

Miranda

Alvaro

Spain

Mononen

Robert Matias

Estonia

Naderi

Fereshteh

Iran

Nikulina

Elizaveta

Spain

Nowakowska

Sylwia

Switzerland

Nowakowski

Jan

Switzerland

Peña-Méndez

Eladia María Spain

Pflipsen

Chrystel

Belgium

Phark

Soo-hyon

Germany

Phark

Soo-hyon

Germany

Piazzon

Nelly

France

Poly

Simon

Spain

Pons

Miquel

Spain

Pop

Aniela

Romania

TNT 2011

Topic Theory and modelling at the nanoscale Nanostructured and nanoparticle based materials Nanostructured and nanoparticle based materials Graphene / Carbon nanotubes based nanoelectronics and field emission

Poster Title Energy dissipation channels in the reflection and adsorption of nitrogen on Ag(111) Bio-sensing of arsenic by S-layer-modified gold nanoparticles Dispersion of multiwall carbon nanotubes in aqueous suspensions Carbon Nanotubes separation techniques – efficiency and selectivity.

Molecular Doping on the Electronic Properties Theory and modelling at of Silicon Nanowires in the [112], [110], [100] the nanoscale and [111] directions Nanostructured and Enhanced tensile strength of thick nanoparticle based dielectrophoretic carbon nanotube fibers by materials TiO2 infiltration Atomic Structural and electronic properties of NanoChemistry some derivatives of C20 Nanofabrication tools & Electron-beam-induced cobalt deposition nanoscale integration Self Assembly of Acetylene-Appended Porphyrin on Au(111) and cycloaddition of 7,7,8,8NanoChemistry Tetracyano-p-quinodimethane (TCNQ) visualized by Scanning Tunneling Microscopy Assembly of 2D ionic layers by reaction of alkali NanoChemistry halides with an organic electrophile – TCNQ Gold (III) and gold nanoparticles interactions NanoChemistry with humic acids Stability and relaxivity of magnetic particles Nanomagnetism and suspensions improved through a simple Spintronics structural reorganization Graphene / Carbon Scanning tunneling microscopy and nanotubes based spectroscopy on edges of epitaxial nanoelectronics and field graphene/Ir(111) emission Graphene / Carbon nanotubes based Direct Observation of Electron Confinement in nanoelectronics and field Epitaxial Graphene Nanoislands emission Nanocalorimetry: a new way to study Other explosives Charge specific CdSe/ZnS quantum dots Nanobiotechnologies enhance amyloid fibrillization of human insulin protein in physiological conditions Theory and modelling at Generation of Coulomb Matrix Elements for the the nanoscale 2D Quantum Harmonic Oscillator Nanostructured and Copper-decorated carbon nanotubes based nanoparticle based composite electrodes for non-enzymatic materials detection of glucose

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Prima Garcia

Helena

Spain

Puente

Antonio

Spain

Rauwel

Erwan

Rauwel

Erwan

Remes

Adriana

Rezanka

Pavel

Rodrigues

Sean

Rusz

Stanislav

Sabater Piqueres

Carlos

Sato

Yoshiko

Segura

Rodrigo

Sorokin

Pavel

Stassi

Stefano

Tilocca

Antonio

Timusk

Martin

Torrellas

Germﾃ｡n

Umemura

Kazuo

TNT 2011

Topic

Poster Title

Nanomagnetism and Spintronics

Prussian Blue Analogue thin films as promising materials of future molecule-based spintronic devices

Low dimensional materials (nanowires, Quantum dot addition energies: magnetic field clusters, quantum dots, and interaction screening etc.) Unusual photoluminescence of undoped hafnia NanoOptics & Norway perovskite nanoparticles synthesized via nonNanoPhotonics aqueous sol-gel process Nanostructured and Conformal coating of nanoporous ﾎｳ-alumina Norway nanoparticle based using Atomic layer deposition: Spinel formation materials and luminescence induced by rare-earth doping Preparation and application of electrochemical Nanostructured and sensor based on Ag-doped synthetic zeolite Romania nanoparticle based modified multiwall carbon nanotube electrode materials for arsenic detection Nanostructured and Application of Bare Gold Nanoparticles in Czech nanoparticle based Open-Tubular CEC Separations of Polyaromatic Republic materials Hydrocarbons NanoOptics & Interaction between dipole emitters and 2D United States NanoPhotonics plasmonic nanoparticle arrays Nanostructured and Change of geometry of ECAP channel to Czech nanoparticle based increase deformation intensity by SPD process Republic materials AlMn1Cu alloy Low dimensional materials (nanowires, Formation of Stable Metallic Nanocontacts by Spain clusters, quantum dots, mechanical annealing etc.) Surface smoothening of single crystal diamond NanoOptics & Japan chip by 0.50-3.0 keV Oxygen ion beam for XFEL NanoPhotonics projection optics Nanostructured and Filling carbon nanotube membranes with Pd Chile nanoparticle based and TiO2 materials Graphene / Carbon Ultrathin diamond nanofilms as possible twonanotubes based Russia dimensional insulators for future nanoelectronics and field nanoelectronics emission Nanostructured and Evaluation of different conductive Italy nanoparticle based nanostructured particles as filler in smart materials piezoresistive composites United Theory and modelling at Molecular Dynamics models of a bioactive glass Kingdom the nanoscale nanoparticle Optical properties of high-performance liquid Estonia Other crystal-xerogel microcomposite electro-optical films Twist-radial oscillations resonance effects in Spain Nanobiotechnologies double-stranded DNA chains Comparative study of DNA窶田arbon nanotube Japan Nanobiotechnologies hybrids using atomic force microscopy

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Topic

Valtr

Miroslav

Czech Republic

Velázquez García

José Joaquín

Spain

Velázquez García

José Joaquín

Spain

Veverková

Lenka

Czech Republic

Villamor

Estitxu

Spain

Nanomagnetism and Spintronics

Yokoyama

Mami

Japan

NanoChemistry

Zaveta

Karel

Czech Republic

SPM Low dimensional materials (nanowires, clusters, quantum dots, etc.) Nanostructured and nanoparticle based materials NanoChemistry

Other

Zhukova

Valentina

Spain

Nanomagnetism and Spintronics

Zvatora

Pavel

Czech Republic

Nanomagnetism and Spintronics

TNT 2011

November 21-25, 2011

Poster Title Voice coil based scanning probe microscopy Photoluminescence of Ag and Li nanoclusters dispersed in glass host Multiphase SiO2-SnO2-LaF3 nanostructured glass-ceramics for simultaneous UV and NIR solar spectrum conversion Effect of gold and silver nanoparticles on interactions of porphyrin-brucine conjugates with oxoanions NO3-. H2PO42-, SO42-, ClO3-, ClO4-, HCO3-, ReO4Optimization of spin injection in Lateral Spin Valves DFT calculation for OH group around Pd on Smodified Au(111) Superparamagnetic transition in nanoparticles of iron oxides Magnetic and transport properties of granular Co-Cu glass-coated microwires Structural and magnetic properties of nanocrystalline lanthanum – strontium manganese perovskites

Tenerife- Spain

Poster Contributions by Topics (92)

Presenting Author

Country

Poster Title

TOPIC: Carbon Nanotubes Based Nanoelectronics and Field Emission France

Single-wall carbon nanotubes quantum dots fabricated by controlled electromigration

Ferrer-Anglada Núria

Spain

Flexible Transparent Electrodes Using Carbon Nanotubes

Gómez-Navarro Cristina

Spain

Discriminating chemically derived graphene conductivity through Electrostatic Force Microscopy

Hague

James

United Kingdom

Tunable graphene bandgaps from superstrate mediated interactions

Jones

Gavin

United Kingdom

Surface Potential Variations in Graphene Induced by Crystalline Ionic Substrates

Karamitaheri

Hossein

Austria

Transport Gap Engineering in Zigzag Graphene Nanoribbons

Kroes

Jaap

Switzerland

DFT studies of hydrogenated and defective carbon nanotubes

Kvashnin

Dmitry

Russia

The strong influence of configurations of graphane islands to electronic properties of graphene/graphane mixing structure

Labunov

Vladimir

Belarus

Novel “Carbon Nanotube/Graphene Layer” Nanostructures Obtained by Injection CVD Method for Electronic Applications

Mijowska

Ewa

Poland

Carbon Nanotubes separation techniques – efficiency and selectivity.

Phark

Soo-hyon

Germany

Scanning tunneling microscopy and spectroscopy on edges of epitaxial graphene/Ir(111)

Phark

Soo-hyon

Germany

Direct Observation of Electron Confinement in Epitaxial Graphene Nanoislands

Sadeghvishkaei Mahta

Canada

A New application of Mesoporous Carbon Nanopearls to Carry the Metal Nanoparticle

Sorokin

Russia

Ultrathin diamond nanofilms as possible two-dimensional insulators for future nanoelectronics

Della Rocca

Maria Luisa

Pavel

TOPIC: Low-Dimensional Materials Amato

Filippo

Diamond-Like Carbon (DLC) chemical vapor deposition Czech Republic technology: Characterization of DLC nano-layers and Artificial Neural Networks for process modelling

Hermosa

Cristina

Spain

Highly electrical conductive, ultralarge and well-ordered MMX nanorods

Kaasbjerg

Kristen

Denmark

Phonon-limited mobility in single-layer MoS2

Sabater Piqueres

Carlos

Spain

Formation of Stable Metallic Nanocontacts by mechanical annealing

TNT 2011

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Poster Title

TOPIC: Nanobiotechnologies Choi

Seong Soo

Korea

Fabrication and Characteristics of Plasmonic Nanopore on the Pyramid for Ultrafast Genome Sequencing

Choi

Seong Soo

Korea

Dynamical Formation of Plasmonic Nanopore and its Optical Characteristics

Gelinsky-Wersing

Dagmar

Germany

Nanoporous impedimetric fibre sensor for the detection of acute inflammation in wounds

Liu

Zunfeng

Netherlands

"Single Walled Carbon Nanotubes as a Scaffold to Concentrate DNA for Studying DNA-Protein Interactions"

Poly

Simon

Spain

Charge specific CdSe/ZnS quantum dots enhance amyloid fibrillization of human insulin protein in physiological conditions

Torrellas

Germán

Spain

Twist-radial oscillations resonance effects in double-stranded DNA chains

Umemura

Kazuo

Japan

Comparative study of DNA–carbon nanotube hybrids using atomic force microscopy

Velázquez García

José Joaquín

Spain

Photoluminescence of Ag and Li nanoclusters dispersed in glass host TOPIC: Nanochemistry

Abdusalyamova

Makhsuda

Tajikistan

Biosorpsion of antimony, nercury and gold at complex conversion of intractable ores

Naderi

Fereshteh

Iran

Atomic Structural and electronic properties of some derivatives of C20

Nowakowska

Sylwia

Switzerland

Self Assembly of Acetylene-Appended Porphyrin on Au(111) and cycloaddition of 7,7,8,8-Tetracyano-p-quinodimethane (TCNQ) visualized by Scanning Tunneling Microscopy

Nowakowski

Jan

Switzerland

Assembly of 2D ionic layers by reaction of alkali halides with an organic electrophile – TCNQ

Peña-Méndez

Eladia María Spain

Veverková

Lenka

Effect of gold and silver nanoparticles on interactions of Czech Republic porphyrin-brucine conjugates with oxoanions NO3-. H2PO42-, SO42-, ClO3-, ClO4-, HCO3-, ReO4-

Yokoyama

Mami

Japan

Gold (III) and gold nanoparticles interactions with humic acids

DFT calculation for OH group around Pd on S-modified Au(111)

TOPIC: Nanofabrication Tools and Nanoscale Integration Mahmud

Syeda Faria Japan

Development of a new technique for sharpening of a diamond knife without facet and ripple formation by low energy Ion beam

Nikulina

Elizaveta

Electron-beam-induced cobalt deposition

TNT 2011

Spain

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Poster Title

TOPIC: Nanomagnetism and Spintronics Arias Mediano

Jose Luis

Spain

Design of Maghemite/Poly(D,L-lactide-co-glycolide) Nanoparticles for Magnetic Fluid Hyperthermia

Guslienko

Konstantin Spain

Thermal relaxation and energy barriers near vortex nucleation field in circular permalloy dot arrays

Hierro RodrĂguez

Aurelio

Spain

Tailoring the magnetization states in thickness modulated NdCo5 films with perpendicular magnetic anisotropy.

Kohout

Jaroslav

Czech Republic Effects of surface in epsilon-Fe2O3 nanoparticles

Pflipsen

Chrystel

Belgium

Stability and relaxivity of magnetic particles suspensions improved through a simple structural reorganization

Prima Garcia

Helena

Spain

Prussian Blue Analogue thin films as promising materials of future molecule-based spintronic devices

Villamor

Estitxu

Spain

Optimization of spin injection in Lateral Spin Valves

Zhukova

Valentina

Spain

Magnetic and transport properties of granular Co-Cu glasscoated microwires

Zvatora

Pavel

Czech Republic

Structural and magnetic properties of nanocrystalline lanthanum â&#x20AC;&#x201C; strontium manganese perovskites

TOPIC: NanoOptics & NanoPhotonics Buencuerpo

Jeronimo

Spain

3D-FDTD Analysis of Absorption Enhancement in Nanostructured Thin Film Solar Cells

Haberko

Jakub

Switzerland

Application of 3D laser nanolithography to the fabrication of photonic crystals

Lahoz

Fernando

Spain

Time resolved fluorescence characterization of oligo(pphenylene ethynylene) based metallic nanorods.

Rauwel

Erwan

Norway

Unusual photoluminescence of undoped hafnia perovskite nanoparticles synthesized via non-aqueous sol-gel process

Rodrigues

Sean

United States

Interaction between dipole emitters and 2D plasmonic nanoparticle arrays

Sato

Yoshiko

Japan

Surface smoothening of single crystal diamond chip by 0.503.0 keV Oxygen ion beam for XFEL projection optics

TOPIC: Nanostructured and Nanoparticle Based Materials Arias Mediano

Jose Luis

Spain

Magnetite/Chitosan Nanocomposite for Magnetic Gemcitabine Targeting to Cancer

Biedma Ortiz

Rafael

Spain

Biodegradable Magnetic Nanomedicine Based on the Antitumor Molecule Tegafur

Biedma Ortiz

Rafael

Spain

Magnetosomes for Anticancer Therapies based on 5Fluorouracil

Bursikova

Vilma

Czech Republic

Plasma deposition of nanocomposite protective coatings on polymer substrates

TNT 2011

November 21-25, 2011

Tenerife- Spain

Presenting Author

Country

Poster Title

Chapartegui

Maialen

Spain

Multifunctional Layers for Safer Aircraft Composites Structures

Chen

Xuecheng

Poland

Template based synthesis of different mesoporous carbon nanostructures

Fernandez Martin

Eduardo

Spain

Nanostructured GMI multilayers deposited onto flexible substrates for low pressure sensing

Gaztelumendi

Idoia

Spain

Self-Sensing behaviour in glass fiber based epoxy laminates using MWCNT

Gong

Hao

Singapore

The study of indium zinc oxide, a material that can combine with porous silicon to form white light emitting diodes

GonzĂĄlez Orive

Alejandro

Spain

"Electrochemical Synthesis and Delivery of Melanin Covered Gold Nanoparticles and Catalytic Activity"

Kalenczuk

Ryszard

Poland

Advances in magnetic silica nanotubes preparation and characterization

Kiessling

Anja

Germany

SiC formation in carbon nanotubes grown from permalloy catalyst particles

Lee

Soo-Keun

Korea

Carbon Nanoflake/ Tin Oxide Composites Gas Sensors for NH3 Detection

Maciejewska

Barbara

Poland

Size of the single domain magnetite particles and MRI parameters

Manea

Florica

Romania

Silver-functionalized carbon nanofibers composite electrodes for Ibuprofen detection

Matys

Sabine

Germany

Bio-sensing of arsenic by S-layer-modified gold nanoparticles

Michalska

Martyna

Poland

Dispersion of multiwall carbon nanotubes in aqueous suspensions

Mononen

Robert Matias

Estonia

Enhanced tensile strength of thick dielectrophoretic carbon nanotube fibers by TiO2 infiltration

Pop

Aniela

Romania

Copper-decorated carbon nanotubes based composite electrodes for non-enzymatic detection of glucose

Rauwel

Erwan

Norway

Remes

Adriana

Romania

Rezanka

Pavel

Czech Republic

Application of Bare Gold Nanoparticles in Open-Tubular CEC Separations of Polyaromatic Hydrocarbons

Rusz

Stanislav

Czech Republic

Change of geometry of ECAP channel to increase deformation intensity by SPD process AlMn1Cu alloy

Segura

Rodrigo

Chile

Filling carbon nanotube membranes with Pd and TiO2

Stassi

Stefano

Italy

Evaluation of different conductive nanostructured particles as filler in smart piezoresistive composites

TNT 2011

Conformal coating of nanoporous Îł-alumina using Atomic layer deposition: Spinel formation and luminescence induced by rare-earth doping Preparation and application of electrochemical sensor based on Ag-doped synthetic zeolite modified multiwall carbon nanotube electrode for arsenic detection

November 21-25, 2011

Tenerife- Spain

Presenting Author Velázquez García

Country

José Joaquín

Poster Title Multiphase SiO2-SnO2-LaF3 nanostructured glass-ceramics for simultaneous UV and NIR solar spectrum conversion

Spain

TOPIC: Other Kang

Dae Joon

Korea

Ferroelectric-gate Field Effect Transistors Based Nonvolatile Memory Devices Using p-type Si Nanowire Conducting Channel

Kim

Duckjong

Korea

Raman characterization of heat spreading in carbon nanotube film

Kim

Duckjong

Korea

High power carbon nanotube heater

Langecker

Jens

9,12-Dithiol-1,2-dicarba-closo-dodecaborane as building Czech Republic block for ligands for surfaces, nanoparticles and metal complexes

Lebar Bajec

Iztok

Slovenia

Two-layer synchronized ternary quantum-dot cellular automata wire crossings

Piazzon

Nelly

France

Nanocalorimetry: a new way to study explosives

Timusk

Martin

Estonia

Optical properties of high-performance liquid crystal-xerogel microcomposite electro-optical films

Zaveta

Karel

Czech Republic Superparamagnetic transition in nanoparticles of iron oxides TOPIC: Scanning Probes Methods

Knotek

Petr

Czech Republic

Utilization of Mechanical Properties´ Imaging for Detection of Au-nanospheres Used as Biomarkers

Valtr

Miroslav

Czech Republic

Utilization of Mechanical Properties´ Imaging for Detection of Au-nanospheres Used as Biomarkers

TOPIC: Theory and Modelling at the Nanoscale Chashchikhin

Vladimir

Russia

Molecular design of a sensor for small analyte molecules based on a dye adsorbed on silica nanoclusters and nanopores

Gómez

Sacha

Spain

On the use of Artificial Neural Networks in Electrostatic Force Microscopy

Kondov

Ivan

Germany

Integrated Services for Multiscale Materials Modelling and Simulation

Martin-Gondre

Ludovic

Spain

Energy dissipation channels in the reflection and adsorption of nitrogen on Ag(111)

Miranda

Alvaro

Spain

Molecular Doping on the Electronic Properties of Silicon Nanowires in the [112], [110], [100] and [111] directions

Pons

Miquel

Spain

NH_3 Molecular Doping of Silicon Nanowires in the [112], [110], [100] and [111] directions

Tilocca

Antonio

United Kingdom Molecular Dynamics models of a bioactive glass nanoparticle

TNT 2011

November 21-25, 2011

Tenerife- Spain