Grazing incidence surface scattering of X-rays

A comprehensive presentation of new developments in the theory of diffuse (off-specular) surface scattering of X-rays is given and illustrated with experimental results on different kinds of films and surfaces. This technique allows the determination of surface and interface morphology through height–height correlation spectra over a wide in-plane wave-vector range (105–1010 m–1). A general method for the determination of the tensorial Green function relevant to the problem is indicated. The Born approximation and the more accurate distorted-wave Born approximation are evaluated. The need for even better approximations is stated and possible methods are indicated. The theoretical results are compared with the results of experiments and non-trivial effects are evidenced. Finally, different methods for the measurements of liquid fluctuation spectra with synchrotron radiation are discussed, demonstrating the ability of this technique to provide more insight into the statistical physics of liquid interfaces down to molecular scales.