ELECTRONIC-STRUCTURE, BIS, CORE-LEVEL XPS AND XAS IN CEPD7 - EXPERIMENTAL AND THEORETICAL-STUDIES

The electronic structure of CePd7 is studied using various spectroscopic techniques (BIS, 3d/XPS and 2p/XAS). The strong delocalization of the Ce 4f electrons, previously suggested by low-temperature specific heat and magnetic susceptibility measurements, is consistent with the spectra we present here. A standard LMTO band structure calculation is performed in the case of CePd7 and its-reference compound YPd7. The bands thus determined, especially the last valence and first conduction bands, mostly arising from Pd 4d and Ce 4f states, are actually hybridized; they provide a good description of the density of states at the Fermi level and a qualitative agreement with Bis spectra. Furthermore the occurrence of satellites in core-level spectra indicates a fairly strongly correlated nature of the 4f states in CePd7. In the next step, the information contained in the LmTo density of states is used to build an impurity Anderson Hamiltonian which incorporates the various Coulomb interactions necessary to analyse the above-mentioned spectroscopic processes within a single set of parameter values for CePd7. Limits and relevance of both theoretical models are discussed.