Influence of side groups on 90° superexchange: A modification of the Goodenough-Kanamori-Anderson rules
1996; American Physical Society; Volume: 54; Issue: 5 Linguagem: Inglês
10.1103/physrevb.54.3011
ISSN1095-3795
Autores Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoA mechanism is suggested which can modify in certain cases the Goodenough-Kanamori-Anderson rules determining the character of superexchange in magnetic insulators; namely, side groups coupled to ligands, which are often present but are usually ignored, may contribute significantly, and may in certain cases even lead to a change in sign of the superexchange interaction. Thus this factor can make the 90\ifmmode^\circ\else\textdegree\fi{} superexchange of half-filled shells antiferromagnetic, in contrast to the usual case. Qualitative arguments and numerical estimates show that this mechanism may be important in the inorganic spin-Peierls compound ${\mathrm{CuGeO}}_{3}$. \textcopyright{} 1996 The American Physical Society.
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