X-ray scattering and x-ray fluorescence from materials with rough interfaces

Abstract

This paper discusses the influence of interface roughness on specular and nonspecular x-ray reflectivity and glancing-incidence x-ray fluorescence (GIXRF). Formulas are derived in the second-order distorted-wave Born approximation for samples consisting of an arbitrary number of layers. The results depend on the root-mean-square value of the interface roughness, its lateral correlation length and its degree of perpendicular correlation, as well as on the degree of jaggedness. Either flat interfaces or graded interfaces can be used as a starting point. It is shown that for GIXRF the latter approach is better. The consequences for diffuse scattering are discussed. Examples are given of calculations of specular reflectivity and GIXRF for layered materials. \textcopyright{} 1996 The American Physical Society.