Electronic structure, BIS, core-level XPS and XAS in CePd<sub>7</sub>: experimental and theoretical studies
E Beaurepaire; J P Kappler; S Lewonczuk; J Ringeissen; M A Khan; J C Parlebas; Y Iwamoto; A Kotani; E Beaurepaire; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; J P Kappler; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; S Lewonczuk; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; J Ringeissen; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; M A Khan; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; J C Parlebas; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; Y Iwamoto; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France; A Kotani; Inst. de Phys. et Chimie des Mater., Univ. Louis Pasteur, Strasbourg, France
Журнал:
Journal of Physics: Condensed Matter
Дата:
1993-08-09
Аннотация:
The electronic structure of CePd<sub>7</sub> 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 the authors present here. A standard LMTO band structure calculation is performed in the case of CePd<sub>7</sub> and its reference compound YPd<sub>7</sub>. 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 CePd<sub>7</sub>. 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 CePd<sub>7</sub>. Limits and relevance of both theoretical models are discussed.
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