f-band ferromagnetism in the periodic Anderson model - a modified alloy analogy
| Autor: | A. Ramakanth, D. Meyer, G. Gangadhar Reddy, Wolfgang Nolting, S Schwieger |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Physics
Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Alloy FOS: Physical sciences Spectral density State (functional analysis) engineering.material Condensed Matter Physics Condensed Matter - Strongly Correlated Electrons Condensed Matter::Materials Science Ferromagnetism engineering Quasiparticle Condensed Matter::Strongly Correlated Electrons General Materials Science Limit (mathematics) Anderson impurity model Phase diagram |
| Zdroj: | Journal of Physics: Condensed Matter. 12:7463-7480 |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/0953-8984/12/33/313 |
| Popis: | We introduce a new aproximation scheme for the periodic Anderson model (PAM). The modified alloy approximation represents an optimum alloy approximation for the strong coupling limit, which can be solved within the CPA-formalism. Zero-temperature and finite-temperature phase diagrams are presented for the PAM in the intermediate-valence regime. The diversity of magnetic properties accessible by variation of the system parameters can be studied by means of quasiparticle densities of states: The conduction band couples either ferro- or antiferromagneticaly to the f-levels. A finite hybridization is a necessary precondition for ferromagnetism. However, too strong hybridization generally suppresses ferromagnetism, but can for certain system parameters also lead to a semi-metallic state with unusual magnetic properties. By comparing with the spectral density approximation, the influence of quasiparticle damping can be examined. 20 pages, 13 figures |
| Databáze: | OpenAIRE |
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