Coherent and diffuse X-ray scattering from a multicomponent superlattice with quantum dots

GaAs-AlAs superlattices with InAs quantum dots grown by molecular beam epitaxy have been studied by high-resolution X-ray diffractometry. It has been experimentally revealed that the maxima of the superstructural diffuse scattering from the quantum dots do not coincide with the angular positions of the coherent superstructural satellites. A statistical theory of diffraction on the superlattice taking into account the spatial correlation of the quantum dots has been developed to explain this effect. It has been shown within this theory that the peak positions of the diffuse component can differ from the maxima of the coherent scattering. X-ray scattering by the multicomponent superlattice have been numerically simulated and the calculation results have been compared with the experimental data.