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 a nd X-ray emission spectroscopy. A series of V2-xMoxO5 compounds was obtaine d 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 lev el increases. The enhancement is due to both Mo 4d and V 3d states and seem s to be relatively unaffected by the hybridization with O 2p states situate d at higher binding energies. The trends in the measured spectra are discus sed in comparison to band structure calculations performed for defect-conta ining supercells. (C) 2001 Elsevier Science B.V. All rights reserved.