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Simple Spectral Density Approach to the Problem of Mixed Valency
Author(s) -
Nolting W.,
Olés A. M.
Publication year - 1981
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221080221
Subject(s) - valency , coulomb , simple (philosophy) , valence (chemistry) , electron , statistical physics , physics , condensed matter physics , valence electron , quantum mechanics , theoretical physics , mathematics , philosophy , linguistics , epistemology
A simple spectral density approach is proposed for the extended Falicov‐Kimball model to describe the phenomenon of mixed valency observed in 4f‐compounds. The general influences of typical model parameters, as for instance the Coulomb interaction g between localized f‐ and itinerant s‐electrons or the s‐f hybridization V , on characteristic properties of intermediate valence compounds are calculated and discussed. Depending on the parameters g and V the theory predicts both first‐and second‐order transitions as found for the Sm chalcogenides.