Resonant Inelastic X-Ray Scattering at Fe L2, 3 Absorption Edges of SrFeOx Oxides (x = 2.46 and 2.82)

Resonant inelastic X-ray scattering (RIXS) spectra at Fe \({{L}_{{2,3}}}\) absorption edges are used to study the electronic structure of SrFeO_2.46 and SrFeO_2.82. The RIXS spectra of SrFeO_2.82 in comparison with those of SrFeO_2.46 are characterized by less intense elastic recombination peaks and less pronounced inelastic spectral features, which is associated with a lower degree of localization of \({{d}^{4}} + {{d}^{5}}\underline L \) states compared to \({{d}^{5}}\) states. The inelastic scattering features of the RIXS spectra are attributed to d–d excitations. At higher excitation energies, where the continuum-excited fluorescence becomes dominant, the X-ray emission spectra are in good agreement with the measurement results of the photoelectron spectra of the valence bands of both SrFeO_2.46 and SrFeO_2.82. It is shown that Tanabe–Sugano diagrams can be used to interpret the RIXS spectra of the SrFeO_2.46 ferrite with trivalent iron ions located both in octahedra and in tetrahedra of oxygen ions.