Inelastic electron scattering spectra of normal and mixed-valent samarium compounds

Abstract

Electron-energy-loss spectra of the Sm 3d (or 4d) core level are found to be identical to within roughly-equal1 eV, irrespective of the valence state of the samarium. However, an energy shift of about 6 eV is observed for the excitation from the 3p level between the divalent and the trivalent samarium. This is explained as arising from the different final states for the d and p core excitation spectra. The strong Hund's-rule coupling for the 4f/sup 7/ final-state configuration overcomes the Coulomb interaction and leads to the nearly identical spectra for the 3d core excitations. Atomic total energy calculations using a relativistic, spin-polarized, density-functional Dirac procedure are performed and the results are in good agreement with the experimental observations.