THE CATALYST | CBC ALUMNI MAGAZINE
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UNIQUE CRYO-NEASNOM SYSTEM FACILITATES INTER-UNIVERSITY COLLABORATION AT THE KECK CENTER By Hannah Schmidt
T
he W.M. Keck Center for Nanoscale Imaging is excited to announce that we have received a new cryo-neaSNOM system from neaspec GmbH.
they exhibit optoelectronic properties that make them ideal for use in highspeed computing, energy harvesting, and light emission. These were the first materials explored using the new system this summer (see figure).
Drs. Brian LeRoy (UArizona Physics), John Schaibley (UArizona Physics), Bob Norwood (UArizona Optics), Erin Ratcliff (UArizona Chemical Engineering and CBC) and Sefaattin Tongay (ASU School for Engineering of Matter, Transport and Energy) secured a National Science Foundation Major Research Instrumentation grant funding to make this possible.
SNOM, or scanning near-field optical microscopy, focuses a light source onto a small, metallized tip, creating a localized electric field. When the tip comes into close proximity with a sample, backscattered light is detected and allows for mapping of the sample. Because the electric field is confined to such a small area, SNOM exhibits 10 nm resolution.
LeRoy and Schaibley use single-dimensional carbon nanotubes to create two-dimensional materials. These materials are extremely thin and flexible, and
SNOM can spatially map electronic, chemical, and physical properties of a sample using techniques like topography, Raman scattering, FTIR, reflectivity,
and photoluminescence. Additionally, this system can probe liquid and solid samples with temperatures as low as 10K (-442° F), making it the only SNOM in the United States with these capabilities. Schaibley and LeRoy will use the new SNOM system to image plasmons confined to their 1D nanotubes and to map excitonic currents in novel semiconductor heterostructures (see figure). Several other research groups representing five different colleges at UArizona and ASU will also benefit from the system. The Mansour group (UArizona Pharmacy) will study biocompatible drug delivery systems. The Norwood group will map thin films of magneto-optical polymers and magnetic nanoparticles. The Ratcliff group will use the SNOM’s higher resolution to understand the previously unclear mechanism of the organic photovoltaic degradation process. Other applications will include astrochemistry, further nanoparticle research, and understanding Alzheimer’s disease. The Keck Center will maintain the SNOM and facilitate training of new users. We look forward to working with users to generate results on this new and innovative system supporting cutting-edge research across Arizona. Find Alumni News and more in the online magazine
cbc.arizona.edu/alumni_friends/ newsletters
Example SNOM image showing Luttinger liquid plasmon oscillations excited in a single walled carbon nanotube (CNT). A. AFM topography image of a CNT. B. Near field amplitude of plasmon excitation. C. Near field phase of plasmon excitation. Image credit: Anna Roche.
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