Electronic structure of Ti metal and TiO 2 powder studied by hard and soft (Cu Kα 1 and Al Kα1) X-ray photoelectron and Auger spectroscopy

Abstract

High-energy X-ray photoelectron spectroscopy (XPS) is of particular importance for minimizing the effects of surface contamination by increasing photoelectron escape depths. In this study high-resolution high-energy Cu Kα 1 and soft Al Kα 1 XPS and Auger electron spectroscopy were used to compare the electronic structure of Ti in TiO 2 powder and Ti metal. The Ti 1s in TiO 2 XPS line is narrower and more symmetric than in Ti metal. A comparison of the relative intensities of the L 23M 23M 45 and L 23M 23M 23 Auger transitions in Ti metal and TiO 2 is consistent with the expected transfer of Ti 3d electrons away from the Ti site in the oxide. The satellites accompanying the Ti 1s XPS line excited by Cu Kα 1 X-rays occur at the same energies as the satellites accompanying the Ti 2s and 2p XPS lines excited by Al Kα 1 X-rays indicating that they do not depend on the core-level, the experimental resolution or inelastic scattering processes.