Magnetic x-ray scattering

The cross sections for magnetic scattering of electromagnetic radiation were derived many years ago but are in general ~10 −6 of the familiar cross sections for charge scattering. The brilliance of present and projected synchrotron sources now make this technique one of considerable promise. We discuss the cross sections and some of the recent results; emphasizing aspects such as the excellent wavevector resolution possible with synchrotron experiments. An important discovery of resonant magnetic scattering was made by Gibbs et al. in holmium. This occurs when the incident photon energy is tuned to certain absorption edges for the magnetic elements. A consequence is an enormous (>10 5 in the case of actinides) enhancement of the intensity, making the technique of particular importance in the study of f element magnetism. We conclude with speculation on some future possibilities of magnetic x-ray scattering.