Publication
Title
Elusive s-f intrasite interactions and double exchange in solids: ferromagnetic versus nonmagnetic ground state
Author
Abstract
From the theory of many-electron states in atoms, we know that there exists a strong Coulomb repulsion, which results in the electronic term structure of atoms and is responsible for Hunds rules. By expanding the Coulomb on-site repulsion into a multipolar series, we derive this interaction and show that it is also present in solids as a correlation effect, which means that the interaction requires a multideterminant version of the Hartree-Fock method. Of particular interest is the case where this interaction couples states of localized ( f) and delocalized ( s) electrons. We show that the interaction is bilinear in the creation/annihilation operators for localized electrons and bilinear in the operators for conduction electrons. To study the coupling, we consider a simple model in the framework of an effective limited configuration interaction method with one localized f-electron and one itinerant s-electron per crystal site. The on-site multipole interaction between the f- and s-electrons is explicitly taken into account. It is shown that depending on the low-lying excitation spectrum imposed by the crystal electric field, the model can lead not only to ferromagnetism but also to a nonmagnetic state. The model is relevant for solids with localized and itinerant electron states.
Language
English
Source (journal)
Journal of experimental and theoretical physics. - Woodbury, N.Y.
Publication
Woodbury, N.Y. : 2009
ISSN
1063-7761
Volume/pages
109:2(2009), p. 286-292
ISI
000270506500014
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
E-info
Web of Science
Record
Identification
Creation 18.11.2009
Last edited 03.08.2017
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