Electron diffraction from crystals containing stacking faults: I

Abstract

The dynamical theory of electron diffraction is applied to the case of a plate-like crystal containing a stacking fault. The effect of the fault is to produce a phase difference in the electron waves diffracted by the two parts of the faulted crystal. Expressions for the wave functions and for the corresponding intensities, predicting interference fringes in the region of overlap of the two parts are derived. It is shown that the problem is one of the interference of three coherent waves, in contrast to the case of the wedge crystal where only two waves are involved. At the Bragg reflecting position the spacing of the fringes is half that corresponding to the extinction distance in the crystal. At large deviations from the Bragg position the predictions of the dynamical theory are asymptotic to those of the kinematical theory. The case of two or more stacking faults on neighbouring atomic planes is also considered.