THE INFLUENCE OF SPECULAR INTERFACE REFLECTION ON GRAZING-INCIDENCE X-RAY-DIFFRACTION AND DIFFUSE-SCATTERING FROM SUPERLATTICES

Superlattices (SL) with a large difference in the refractive index bet ween the alternating layers give rise to specular reflection from the intrinsic interfaces of the SL which proves very efficient for small i ncident or exit angles near the critical angle of total external refle ction. This influences the intensity of grazing incidence X-ray diffra ction (GID) and non-specular X-ray scattering (NSXR). Additional peaks were found besides the common features. They are explained by waves s cattered in transmission geometries and measured above the sample surf ace due to subsequent specular interface reflection. The experimental findings are interpreted by Umweganregung in terms of the distorted wa ve Born approximation (DWBA).