THE ELECTRONIC-STRUCTURE OF NIO INVESTIGATED BY PHOTOEMISSION SPECTROSCOPY

New experiments on the electronic structure of NiO and Li doped NiO obtained by photoemission and inverse photoemission spectroscopy are presented. The data suggest that the photoemission spectra for the oxygen bands correspond to the oxygen band structure while the excitation spectra of the d-states should be described by an Andersson model or a cluster model, meaning that this part of the excitation spectrum has only little relevance to the band structure. Data on Li doped NiO show that the Fermi energy is at 1.4 eV above the 4T1 final state structure and the doping creates an impurity band roughly in the middle of the optical gap.