Resonant 3 d, 3 p and 3 s Photoemission in Transition Metal Oxides Predicted at 2 p Threshold

Abstract

We present calculated 3 d , 3 p and 3 s resonant photoemission (RPE) spectra in the transition metal (TM) compounds CuO, NiO, CoO, FeO, MnO and TiO 2 at TM 2 p core threshold on the basis of a cluster model. Our model includes the intraatomic multipole electron-electron interactions and the hybridization between transition metal ions and ligand. The imaginary part of the self-energy matrix of the intermediate state is calculated by taking into account the 2 p 3 d 3 d , 2 p 3 d 3 p , 2 p 3 d 3 s and 2 p 3 p 3 p Coster-Kronig decay, which guarantees a sum rule between the integrated RPE spectra and absorption spectra. The dependence of RPE on the incident photon energy tuned to various multiplet structures of TM 2 p absorption spectra is shown to be useful to identify the second order optical process, which is argued to include much Auger decay component. It is also shown, by a comparison with experiment, that the present 3 d RPE contributes to a removal of discrepancies of estimated parameter values among analyses of other spectra.