Photoemission study of pristine and Ni-doped SrTiO3 thin films

Abstract

We combined photoelectron spectroscopy with first-principles calculations to investigate electronic properties of SrTiO3 doped with Ni impurities. High-quality epitaxial pristine SrTiO3 and SrTiO3:Nix films with x=0.06 and 0.12 were prepared by pulsed laser deposition. Electronic band structure calculations for the ground state, as well as one-step model photoemission calculations, which were obtained by means of the Korringa-Kohn-Rostoker Green's function method, predict the formation of localized 3d-impurity bands in the band gap of SrTiO3 close to the valence band maxima. The measured valence bands at the resonance Ni 2p excitation and band dispersion confirm these findings.