Magnetic X‐Ray Scattering

Abstract

There are two regimes of importance in magnetic x‐ray scattering, characterized by the incident photon energy relative to the positions of the absorption edges in the system under study. These are the nonresonant and resonant limits to the cross‐section. This article provides an overall background to the theoretical and experimental principles of nonresonant and resonant magnetic x‐ray scattering. The experimental techniques are very similar to standard synchrotron x‐ray diffraction experiments; therefore discussion of the beamlines and spectrometers are limited, with only those elements particular to magnetic scattering, such as polarization analyzers, discussed in any detail. At high incident photon energy, it is possible to perform inelastic experiments utilizing the nonresonant magnetic scattering terms in the cross‐section. This allows for the measurement of magnetic Compton profiles (projections of the momentum density of the magnetic electrons, along a given direction). Magnetic Compton scattering may only be applied to ferromagnets, because of the incoherent nature of the inelastic scattering, and the technique differs in many aspects of its practical implementation from the diffraction experiments discussed here.