Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MI: Fachverband Mikrosonden
MI 8: Poster – Microanalysis and microscopy
MI 8.7: Poster
Mittwoch, 28. März 2012, 15:00–17:30, Poster E
Quantitative STEM of Sn-Pd Nanoparticles with Core-Shell Structures — •Dietrich Häußler1, Bernhard Schaffer2,3, Ferdinand Hofer3, and Wolfgang Jäger1 — 1Microanalysis of Materials, Christian-Albrechts-University Kiel, 24143 Kiel, Germany — 2SuperSTEM Facility, Daresbury Laboratory, WA4 4AD, Warrington, UK — 3Institute for Electron Microscopy, Graz University of Technology, 8010 Graz, Austria
Aberration-corrected high-resolution scanning TEM (STEM) and spectrum-imaging using X-ray (EDXS) and electron energy loss (EELS) signals are combined to quantitatively characterize crystalline Pd-Sn nanoparticles with a core-shell structure. The crystallographic structure of the particle core and shell was determined from the Fourier-filtered periodic back-transformations of STEM bright-field images and by applying a novel STEM diffraction-imaging (DI) technique. In an areal scan, convergent beam electron diffraction patterns are acquired, resulting in a set of data that contains the diffraction information for each image coordinate of the nanoparticle image. The evaluation of such '4D' datasets can be used to obtain by back-projection 2-dimensional dark-field maps that highlight regions of equivalent crystallographic structure and orientation. It is concluded that the approach can be used in monitoring chemical reactions or the degradation of composite nanoparticle materials. - B. Schaffer, now: Gatan GmbH, München, Germany. - We thank F. Liu and X. B. Zhang (Zhejiang University, Hangzhou, China) for provision of samples.