Influence of roughness profile on reflectivity and angle-dependent X-ray fluorescence

The theory of X-ray scattering from rough interfaces using the second-order distorted-wave Born approximation is reviewed. For specular reflectivity a new expression is given which smoothly connects the Névot-Croce and Debye-Waller expressions. The shape, of the reflectivity curve depends not only on the average roughness, but also on the lateral correlation of the roughness profile. Using the same theory, the several ways in which roughness can influence angle-dependent X-ray fluorescence are evaluated. Finally, possible shapes for the roughness correlation function are discussed