Electronic structure of the mixed-valent system V2-xMoxO5

We have investigated the electronic structure of the mixed-valent system V2-xMoxO5 with varying doping concentration by means of X-ray photoelectron and X-ray emission spectroscopy. A series of V2-xMoxO5 compounds was obtained by the hydrochemical method. By comparing the XPS valence band with the V L alpha. O K alpha and Mo L beta (2.15) XES spectra we could localize the V 3d, Mo 4d and O 2p states in the valence band. It has been found that in the course of the Mo doping, the density of states just below the Fermi level increases. The enhancement is due to both Mo 4d and V 3d states and seems to be relatively unaffected by the hybridization with O 2p states situated at higher binding energies. The trends in the measured spectra are discussed in comparison to band structure calculations performed for defect-containing supercells. (C) 2001 Elsevier Science B.V. All rights reserved.