An experimental study of the q⊥-dependence of X-ray resonant diffuse scattering from multilayers

A study of X-ray resonant diffuse scattering from the W/Si multilayer was performed to examine its dependence on the momentum transfer normally to the specular diffraction plane, q⊥. The data obtained show two evident disagreements with the present theoretical approximations. Firstly, when the incident angle was approximately equal to the Bragg angle, additional scattering concentrated in the specular diffraction plane was observed. Secondly, the q⊥-dependence of the quasi-Bragg scattering intensity obtained from these experiments is not the same, at least at the small momentum transfer, as can be obtained from the scans in the specular diffraction plane, having tendency to accumulate near this plane. The possible reasons for these phenomena are discussed.