Magnetic absorption of hard x-rays: New aspects

The study of magnetic XANES of circularly polarized hard x-rays at the K-edges of 3d- and at the L-edges in 4f- and 5d-elements in ferro(i)magnetic materials is a powerful method to study in an element-selective manner magnetic aspects of the electronic structure of solids. It is demonstrated on the basis of simplified single-particle band-structure pictures that for the 5d-elements polarized by 3d- neighbors, information on the local spin and orbital moments can be directly deduced from the magnetic L2, 3-spectra. Although the interpretation of the corresponding data of the rare earth is much more complicated interesting insights in the variation of their magnetic moment in different chemical environments and the binding character are possible as shown for Tb/Fe multilayered sample. The first observation of temperature-dependent changes of the magnetic absorption profile in invar alloys in comparison with theoretical calculations probe the applicability of magnetic K-edge spectroscopy on spin-fluctuating systems.