Theoretical basis of photon spectroscopies

Abstract

The theoretical basis of x-ray spectroscopies most commonly used in the investigation of magnetic systems is reviewed. A systematic derivation of the cross sections of the different processes (elastic and inelastic, resonant and non-resonant scattering, absorption spectroscopies and dichroism) is attempted, emphasizing the conceptual common aspects of these techniques and, at the same time, the variety of information that they deliver.