Mott-Hubbard type insulating nature of epitaxial LaVO3 thin films

The electronic structure of epitaxial LaVO3 (001) thin films have been studied using resonant photoemission spectroscopy (RPES) and x-ray absorption near edge spectroscopy (XANES) measurements. The RPES study confirms the mixing of V 3d with O 2p states and the V 3d character at 6.9 eV and 1.5 eV binding energies, respectively. The resonant behavior of V 3d state suggests 3d(n-1) final state, ascribed with an incoherent structure, and is attributed as a lower Hubbard band. The smaller value of crystal field splitting energy observed in O K-edge XANES spectrum and the hopping parameter obtained from simulations reveal a weaker hybridization between ligand O 2p and metal V 3d orbitals. Combined spectra of occupied and unoccupied states suggest the Mott-Hubbard type insulating nature of the epitaxial LaVO3 thin films at room temperature, different from its bulk counterpart, which is placed intermediate between the charge transfer and Mott-Hubbard regime.