Metal-insulator transition for V2O3 powder observed using a soft x-ray emission spectrometer

A bulk-sensitive measurement is required in order to observe changes in the electronic states across metal-insulator transition (MIT). We have measured unoccupied and occupied electronic states for V2O3 powder above and below the MIT by O K partial fluorescence yield (PFY) and soft x-ray emission spectroscopy (SXES) using a soft x-ray emission spectrometer. The PFY spectra for the metallic and insulating phases show an O K edge shift of ∼0.5 eV and a change in intensity near the edge. The SXES spectra excited by the incident photon energy near the O K threshold also show a spectral change above and below the MIT. This study shows that the soft x-ray spectrometer allows us to measure the bulk electronic states of powder samples where surface cleaning is difficult. (author)