X‐ray topographic study of antiphase domain boundaries in ferroelectric ferroelastic GdDy(MoO4)3crystals. II. Evaluation of the additional translation vector

摘要

Antiphase domain boundaries (APB’s) can be considered as planar defects introducing a phase shift between the structure factors of both domains. Two different geometries of APB’s are considered here, corresponding respectively to Laue–Bragg and Laue–Laue cases for x‐ray propagation. Comparison between experimental and computer simulated x‐ray topographic sections in both cases leads to an evaluation of the additional translation vector Dgr;fat the APB of the order ofa/30 resulting from a local expansion of the lattice. A simple interpretation for this result is given.