Inelastic x-ray scattering study of the metal-antiferromagnetic insulator transition in V2O3

We use inelastic x-ray scattering to study changes in the electronic excitation spectrum due to the metal-to-antiferromagnetic insulator transition in V2O3. The spectra reveal three principal features emdash a plasmonlike excitation at an energy loss of 12eV which disperses with momentum transfer, a nondispersive peak at 9.2eV, and a shoulder near 2eV that appears only in the antiferromagnetic insulator phase. The 9.2eV peak can be associated with a new type of valence band exciton, while the low energy shoulder is consistent with the opening up of a Hubbard gap. copyright 1996 The American Physical Society