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Model Calculations of Electron Spectra for Ce Mixed Valence Compounds

  • O. Gunnarsson
  • K. Schönhammer
Part of the NATO ASI Series book series (NSSB, volume 117)

Abstract

The 4f level plays an important role for many properties of Ce compounds, and its occupancy, nf, and coupling, Δ, to the conduction states are of great interest.1, 2 From thermodynamic data it has been inferred that Δ is small (∽ 0.01 eV) and that, depending on the compound, nf can have any value between zero and one.1, 2 Recent spectroscopic measurements have, however, suggested that both nf and Δ are much larger than believed earlier.1, 2 In the following, we develop methods for calculating electron spectra, and we deduce new values of nf and Δ from these calculations. The calculations are performed for a generalized Anderson impurity model. Anderson3 and Ramakrishnan4 realizedthat for this model 1/N can be treated as a small parameter, where N is the degeneracy of the 4f level. This idea has been used to develop methods for calculating thermodynamic properties.4–6 We have presented a method for calculating electron spectra at T = 0, which is particularly suited for a large degeneracy.7, 8 A diagrammatic method was later developed by Coleman9 for systems where the double occupancy of the f-level is suppressed. Here we briefly describe our method7, 8 and some applications.10–13

Keywords

Conduction State Double Occupancy Final State Effect Large Degeneracy Core Spectrum 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1984

Authors and Affiliations

  • O. Gunnarsson
    • 1
    • 2
  • K. Schönhammer
    • 3
  1. 1.Max-Planck Institut für FestkörperforschungStuttgart 80Federal Republic of Germany
  2. 2.Institute for Theoretical PhysicsUniversity of California at Santa BarbaraSanta BarbaraUSA
  3. 3.I. Institut für Theoretische PhysikUniversität HamburgHamburg 36Federal Republic of Germany

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