Electron precession microdiffraction as a useful tool for the identification of the space group. Application of the identification of the space group.Journal of microscopy, 227(2):157-171
Resume: The possible space groups of a crystal can be identified from a few zone axis microdiffraction patterns provided the position (and not the intensity) of the reflections on the patterns is taken into account. The method is based on the observation of the shifts and the periodicity differences between the reflections located in the first-order Lane zone (FOLZ) with respect to the ones located in the zero-order Laue zone (ZOLZ). Electron precession microdiffraction patterns display more reflections in the ZOLZ and in the FOLZ than in the conventional microdiffraction patterns and this number increases with the precession angle. It is shown, from the TiAl example given in the present study. that this interesting feature brings a strong beneficial effect for the identification of the possible space groups since it becomes very easy to identify unambiguously the FOLZ/ZOLZ shifts and periodicity differences. In addition. the diffracted intensity on the precession patterns is the integrated intensitv and this intensity can also be used to identify the Laue class.
Equipe: Département SI2M : Microstructures et Contraintes