Scattering-path analysis and magnetic scattering properties of Fe/Ag(100) films: A temperature-dependent magnetic EXAFS study

Magnetic extended x-ray absorption fine structure (MEXAFS) is the spin-dependent counterpart of the well established extended x-ray absorption fine structure (EXAFS) technique. By means of MEXAFS, it is not only possible to analyze the local magnetic structure but also to probe magnetic fluctuations. For a fundamental understanding of this technique, we studied bulklike Fe films on a Ag(100) single crystal substrate by comparing the experimental data to ab initio calculations. The measurements were carried out at different temperatures. To model the temperature dependence, originating from lattice vibrations and spin fluctuations, the rigid band model was applied. The present study enables us to understand the differences in the fine structure of spin-averaged and magnetic EXAFS, to identify the scattering paths contributing to the EXAFS signal, and to reproduce the experimental spectra even with a simple rigid band model separating spin fluctuations from lattice vibrations.