Experimental and Theoretical Investigation of the Pre-Peaks at the Ti K -Edge Absorption Spectra in TiO 2

Abstract
The available calculated density of states of TiO2 does not predict the very first weak peak at the onset of the Ti K-edge absorption spectra indicating that this feature is not simply due to a one-electron (dipole) transition. In this short paper we present a joint experimental and theoretical study of all the three weak pre-peaks at the Ti K-edge of TiO2. Our interpretation takes into account both dipole and quadrupole transitions as well as the influence of the core hole effect.