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 e xcitation spectrum due to the metal-to-antiferromagnetic insulator tra nsition in V2O3. The spectra reveal three principal features- a plasmo nlike excitation at an energy loss of 12 eV which disperses with momen tum transfer, a nondispersive peak at 9.2 eV, and a shoulder near 2 eV that appears only in the antiferromagnetic insulator phase. The 9.2 e V peak can be associated with a new type of valence band exciton, whil e the low energy shoulder is consistent with the opening up of a Hubba rd gap.