A dynamical theory for the X-ray diffraction from the partially relaxed layers

The dynamical theory for X-ray diffraction from the bilayer crystal structure with different lateral periods of the crystal unit cells (lateral mismatch) is considered in the present paper. The amplitudes of the principal diffraction waves and all harmonics conditioned by the lateral mismatch are calculated. The formation of the Bragg peaks is analysed taking into account the sphericity of the incident beam wave front set. The connection between the parameters of the coherent diffraction potential in the partially relaxed (epitaxial) crystals and the microscopic characteristics of the dislocations is also discussed.