Theory of 3d Core Level Spectra of CeO2and Metallic Ce Compounds

Core level spectra for a mixed valent insulator CeO 2 and typical mixed valent metallic Ce compounds are discussed on the basis of the filled band Andersom model, which is found to give sufficiently correct core spectra even for a metallic system when the spin and orbital degeneracy of 4 f orbitals is large. A remarkable difference in the 3 d core photoemission spectrum and an apparent similarity in the 3 d -core photoabsorption spectrum between CeO 2 and metallic Ce compounds are consistently explained and an expected difference in the resonant photoemission spectrum near the Ce 3 d threshold between the two systems is discussed. The 4 f 3 configuration of Ce atom is taken into account in the calculation and its effect on core spectra is discussed. The analysis of core spectra neglecting the 4 f 3 configuration can be shown to underestimate the Coulomb interaction between 4 f electrons. So far proposed assignment for peak of core spectra is critically examined.