Microscopy service centre: our analytical tools

To help our customers with their research, OCAS’s microscopy service centre is equipped with a number of state-of-the-art microscopes, from macro to atomic spatial resolution, attached with chemical and crystallographic detectors.

FEG-SEM, INCLUDING EBSD

Scanning electron microscopy (SEM) provides morphological and elemental information. Our SEM (JEOL) is equipped with a Field Emission Gun (FEG), which greatly enhances available electron image resolution (down to a few nm), necessary to observe fine-grained microstructures, surface defects, thin coatings, etc. The attached Electron Backscattered Diffraction (EBSD) detector is used for phase/structure identification and lattice orientation analysis of crystalline samples. Our EBSD system is an Oxford Instruments fast detector, used with Aztec software for fast and automated indexation of EBSD patterns. Energy Dispersive Spectrometer (EDS) and Wavelength Dispersive Spectrometer (WDS) detectors are also attached to enable chemical distribution analysis.

FEG-EPMA WITH SXES DETECTOR

Our latest generation JEOL FEG-Electron Probe Microanalyzer (EPMA) is widely used in industry and academia to relate microstructural features to their chemical composition. The FEG delivers a bright and stable electron beam over a wide range of analytical conditions that are especially suitable for performing imaging and quantitative analysis at high (submicron) spatial resolution. Elements from B to U can be detected even at very low quantity (<0.1wt%). A Soft X-ray Emission Spectrometer improves the analytical performance of our EPMA towards the quantification of light elements (Li to F). The detection limit of this spectrometer is 5 to 10 times better than the classical WDS. The energy resolution of 0.3eV enables us to probe the chemical state of elements from their spectrum peak shape.

FIB/SEM DUAL BEAM

The Thermo Scientific Focused Ion Beam (FIB)/SEM dual-beam microscope is used for both analytical applications and specimen preparation for Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT). The state-of-the-art ion and electron columns allow us to obtain

higher quality SEM and FIB images and accelerate sample preparation by more than 5 times compared to our previous FIB/SEM system. The operational speed can be further enhanced by the dedicated automatisation software which allows the use of pre-designed templates for the partial preparation of multiple samples without the presence of the operator. In addition to the superior speed, the new FIB/SEM system has enhanced analytical capabilities achieved by retractable back-scattered electron (BSE), scanning transmission electron microscopy (STEM), and EDS detectors. These detectors allow us to obtain higher resolution images and perform more sensitive compositional analysis.

(S)TEM

Thanks to its ease of use and high efficiency, OCAS’s TEM is ideal for industrial analytical characterisation. The FEG enables atomic resolution (S)TEM imaging, and the Super-X EDS system has 4 in-column EDS detectors with unique cleanliness, which offers fast and precise chemical analysis in nanoscale. An array of high resolution images can be automatically acquired and stiched to obtain a larg final image. Large area correlative imaging at high resolution by the fully automated and unattended software pack allows researchers to preserve the context of their observations while also providing statistically robust data. The innovative Automated Particle Workflow (APW) pack can get the nanoparticle parameters – like size, area, perimeter, shape, etc. – in an automated way. It can exponentially increase precipitate analysis efficiency with much better statistics.

APT

OCAS has access to a Cameca APT. This instrument incorporates the advanced reflectron design and enhanced detector performance (detection efficiency ~ 50%) and adds all the benefits of advanced laser pulsing capable of repetition rates of up to 500 kHz. During the past several years, this APT has supported OCAS with an advanced characterisation of precipitates, coatings, grain and phase boundaries.