Variation of emission yield of X-rays from crystals with diffraction condition of exciting electrons

Abstract

The X-ray intensity of Zn Kα radiation emitted from clean cleavage surfaces (110) of zincblende crystals excited by fast electrons, which impinge on the surfaces in the same way as in ordinary electron diffraction experiments, was measured under various diffraction conditions of exciting electrons. The electron energy was about 30 keV. It was found that the X-ray intensity decreases at Bragg conditions by about 10–20%, in an asymmetric way with respect to the glancing angle of the electrons. Some of features of such an anomaly in X-ray intensity have been discussed on the basis of a two-wave dynamical theory of electron diffraction taking account of the phenomenological absorption.