Effect of La doping on the electronic structure of SrTiO3

Abstract

For undoped-SrTiO3 and La-doped SrTiO3 single crystals, X-ray photoemission spectroscopy (XPS) measurements were performed with monochromatcd Al Kα radiation. Valence band (VB) spectra of as-fractured SrTiO3 exhibit two peaks, P1 and P2, arising from the O 2pπ and O 2pσ bonding orbitals, respectively. Upon adding 3.0 atm% of La to SrTiO3, the valley between P1 and P2 disappears in the VB spectrum. Calculated VB spectra obtained from a molecular orbital calculation reproduce well the experimental XPS spectra for the samples.