Studies of polycrystalline materials by Pseudo Kossel technique

In contrast to the Kossel Technique the Pseudo Kossel Technique (PKT) is mainly used for investigations of single crystals to determine the crystal structure, the crystallographic orientation and lattice parameter of the specimens so far. Though the PKT has yet large possibilities and is well-suited also for micro range investigations, the application for the characterization of polycrystalline materials is not common. The complicated configuration of the reflex sections in polycrystals, caused by grain boundary effects, usually makes it very difficult to evaluate them. The studies have been carried out at Al and BaTiO₃ polycrystals. Thus, for the first time the successful application of the technique to a ceramic was demonstrated. The dependence of the reflex length on the grain size was investigated by simulation. It is shown that this technique allows precise determination of correlation between neighbor grains, since one diffraction pattern contains contributions from several grains. As a result one obtains for example the relative orientations of neighbor grains, which influence among other things the electrical and mechanical properties. Received: 5 November 1998 / Revised: 26 March 1999 / Accepted: 3 April 1999