X-ray specular reflection under conditions of extremely asymmetric noncoplanar diffraction from a bicrystal

The angular dependence of the intensities of X-ray specular reflection has been rigorously analyzed under conditions of noncoplanar grazing Bragg diffraction in a crystal coated with a crystalline film (bicrystal). It is shown that the anomalous angular dependence of the specular-reflection intensity is extremely sensitive to the thickness (from fractions of a nanometer up to several nanometers), deformation, and the amorphization degree of the crystalline films. The optimum conditions for recording intensities are attained at grazing angles equal to 1.5–4.0 of the critical angle of the total external reflection.