Theoretical description of the intensity of crystal-truncation-rod scattering modulated by a Bragg reflection

Abstract

Modulation of the intensity of crystal-truncation-rod (CTR) scattering caused by a Bragg reflection, which is a multiple-wave X-ray diffraction phenomenon, is generally formulated. This phenomenon is sensitive to the phase of the CTR scattering amplitude, and can be used to investigate mesoscopic-scale small strain field in a crystal, which can be difficult to be found by only intensity measurement of the CTR scattering around a Bragg point. Conditions are presented under which a strain field gives only a slight change in the intensity of CTR scattering but largely affects the phase of it. We demonstrate analytically that, even in such a case, the strain field can be investigated by measurement of the intensity of CTR scattering modulated by a Bragg reflection.