The Borrmann effect and the structural perfection of dislocation-free InSb crystal

The characteristics of X-ray anomalous transmission in a dislocation-free InSb crystal are investigated by means of a single crystal diffractometer. The coherent and diffuse components of the integral reflectivity, the static Debye-Waller factor, the coefficient of X-ray absorption dire to diffuse scattering, the characteristic radius, and the concentration of microdefects are determined using the dynamic theory of X-ray diffraction ill crystals with randomly distributed microdefects. It is established that the degree of suppression of the Borrmann effect is not very large for Be 220 reflection and increasing with the increasing order of reflection. Nevertheless, for the high-order 440 reflection, which is much more sensitive to slight structural distortions, the level of anomalous transmission of X-rays still remains high at relatively large value of absorption. It is possible to describe the experimental results only by taking into account the dynamic phenomenon of anomalous transmission for the diffuse component of scattering, which, in this particular case, plays an essential role. It is shown that the predominant type of microdefects is rather large (radius is equal approximately 0.3 mu m) with relatively low concentration (approximately 5.10(6) cm(3)).