Standing-wave-grazing-incidence x-ray diffraction from polycrystalline multilayers

The intensity of x-ray diffraction from a polycrystalline multilayer in a grazing-incidence scattering geometry is modulated by a standing wave created by the interference of the radiation transmitted through the multilayer stack with the wave field specularly reflected from the superlattice interfaces. This effect is used for the structure investigation of Nb/Si periodic multilayers. The experimental data have been modeled using the distorted-wave Born approximation and a good correspondence with the experiments was achieved, and it was possible to determine the thicknesses of crystalline and amorphous parts of the Nb layers as well as the mean size of the crystallites.