Dynamical theory of the images of microtwins as observed in the electron microscope: Part II : overlapping domain wall boundaries

The two-beam dynamic theory of the electron transmission microscopie fringe images of microtwins is discussed, in contrast to Part l, it is now assumed that the parent crystal and microtwin are both close to an orientation for reflection. The excitation errors are then slightly different. This situation occurs in BaTiO₃,  CoO, NiO, where the twins are ferroelectric or antiferromagnetic domains characterized by smalI twin vectors and limited by parallel coherent boundaries inclined with respect to the foil surfaces.
If the thickness of the microtwin is small, the anomalous absorption for the microtwin can be neglected. It can then be shown that the images are similar to stacking fault images defined by a phase angle depending on the diffraction conditions and on the microtwin thickness.