Polarization dependence of resonant soft x-ray emission spectra in Ce compounds

The electronic structures of Ce compounds have been investigated by means of resonant soft x-ray emission spectroscopy (RXES) excited at resonant energy range of Ce 3d → 4f absorption. Polarization dependence of the RXES shows information on concerning electronic states. In CEO₂, the Ce 4f → 3d RXES spectra are interpreted as electronic structures hybridized between 4f⁰ and 4f¹v states. Peaks appearing in the spectra are attributed to bonding, nonbonding, and antibonding states between those states, while the spectra of CeRh3 cannot be explained by only using the hybridization between 4f⁰ and 4f¹v states. The spectra have large broad Raman peak, especially when the excitation photon energy is set at satellite of Ce 3d → 4f absorption. We attribute the origin of the broad Raman peak to hybridization states involving electron-hole pairs.