Evidence for very high order laue zone (VHOLZ) lines in CBED patterns

Abstract

It is well known that High Order Laue Zone (HOLZ) line analysis is a powerful tool to study lattice parameter changes due to local chemical composition and microstrain, in addition to determining crystal symmetry. One of the first approaches described by Ecob et al for indexing the HOLZ reflections does not simulate all the observed HOLZ lines. Therefore a more complete computer program for indexing all the observed HOLZ reflections based on kinematical conditions has been developed using the visibility criterion originally developed for Kossel lines. This approach is easy and more accurate. With this technique we have been able to identify very high order Laue zone lines (>3rd order) in low symmetry orientations and index them.Figs, la and lb are computer simulations which show the indexed HOLZ reflections for the second order (SOLZ) and fourth order Laue zone (FOROLZ) in the <116> zone axis. The corresponding defect HOLZ lines in the transmitted disk from pure Al are shown along with computer-simulated patterns for both the SOLZ and FOROLZ in Figs. 2a and 2b respectively.