Site-specific valence-band photoemission study of α-Fe₂O₃

We have measured the site-specific valence electronic structure of α-Fe₂O₃ by using a spatially modulated x-ray standing wave as the excitation source for photoemission. Contributions to the valence-band density of states from oxygen and iron ions are separated by this method. Both a bonding and nonbonding state originating from oxygen ions are obtained. The valence densities of states from iron agree well with predictions based on configuration-interaction cluster calculations by Fujimori et al. [Phys. Rev. B 34, 1318 (1986)] which considered charge transfer from ligand to metal. The effects of strong hybridization between Fe and O valence states to x-ray emission and resonance photoemission are also evident.