Resonant photoemission determination of the valence electronic structure of Cr2O3

Abstract

Resonant photoemission measurements have been performed on well characterized, stoichiometric (1012) surfaces of single-crystal Cr2O3 using synchrotron radiation. A strong resonant enhancement of the highest-lying valence-band states is observed across the Cr 3p → 3d excitation threshold. In light of the similarity of the resonance in Cr2O3 with that of Ti2O3 and V2O3, we conclude that Cr2O3 is a Mott-Hubbard insulator. Cr 3d - O 2p hybridization is evidenced by the presence of the similar, but weaker, resonant enhancement in the O 2p valence-band region.