High-resolution Gd 4d photoemission from different intermetallic compounds

High-resolution x-ray photoemission from the core 4d Gd level enabled the testing of two possible approaches which can be applied to spin-dependent interactions. The interaction of the 4d hole with the half-filled 4f shell, together with spin-orbit coupling, determines the complex shape of the spectra. It is possible to describe the energy spread of the multiplet using as well the one electron as the many-electron model. The observed intensity ratio of particular lines within the multiplet can be described only partially by the existing models. The first, low-binding-energy lines, which are related to the highly spin-polarized electronic states, exhibit intensity lower than expected in the many-electron model. The one-electron model may be applicable for this behavior taking into account possible linear polarization of the x rays. The behavior of the linewidth of the multiplet components can be explained using the lifetime broadening and the analysis of the possible decay channels by the 4d4f4f and 4d5p5p super-Coster-Kronig process.