Scanning Electron Diffraction in the TEM for the characterization of dislocations in minerals

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Marco E. Ciriotti
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Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy

Scanning Electron Diffraction in the TEM for the characterization of dislocations in minerals

Messaggio da Marco E. Ciriotti » sab 15 set, 2018 12:27

Prossima pubblicazione.

▪ Nzogang, B.C., Mussi, A., Cordier, P. (2018): Application of Scanning Electron Diffraction in the Transmission Electron Microscope for the characterization of dislocations in minerals. Mineralogical Magazine, 82, (in press).

We present an application of scanning electron diffraction for the characterization of crystal defects in olivine, quartz and phase A. In this mode, which takes advantage of the ASTARTM module from NanoMEGAS, a slightly convergent probe is scanned over the sample with a short acquisition time (a few tens of ms) and the spot patterns are acquired and stored for further post-processing. Originally, orientation maps were constructed from automatic indexing at each probe location. Here we present another application where images are reconstructed from the intensity of diffraction spots, producing either so-called “virtual” bright- or dark field images. We show that these images present all the characteristics of contrast (perfect crystal or defects) of conventional TEM images. Data being acquired with a very short time per probe location (a few tens of milliseconds), this technique appears very attractive for the characterization of beam-sensitive materials. However, since the acquisition is done at a given orientation, fine tuning of the diffraction conditions at a given location for each reflexion is not possible. This might be a difficulty for some precise, quantitative contrast analysis.
Marco E. Ciriotti

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