Spin‐polarized XANES: theoretical analysis of the Ni K‐edge of NiF₂

Abstract

Theoretical interpretations of spin-dependent X-ray absorption near edge structure (XANES) spectra measured by selectively monitoring of the Ni K-beta emission while scanning the excitation energy through the Ni K absorption edge have been performed. Analysis is based on a combination of selfconsistent spin-polarized calculation of muffin-tin potential and a full multiple scattering theory of X-ray absorption. This approach allows us to separate the influence of dipole transition matrix elements and the density of empty electronic states on spin-dependent XANES. It is found that the matrix elements affect splitting between spin-up and spin-down spectra only near the absorption threshold, while differences in densities of states slightly shift the spectra in the region 25 -35 eV above the main edge. The effects of the multielectron-term-dependent broadening of spin-dependent XANES and mixing of purely spin-polarized spectra were taken into account.