Magnetovolume effect of itinerant electron ferromagnets
2005; IOP Publishing; Volume: 18; Issue: 2 Linguagem: Inglês
10.1088/0953-8984/18/2/013
ISSN1361-648X
AutoresYoshinori Takahashi, Hiroki Nakano,
Tópico(s)Advanced Condensed Matter Physics
ResumoThe magnetovolume effect of itinerant electron magnets is discussed by the explicit examination of the volume dependence of the spin fluctuation free energy. Magnetic Grüneisen parameters are introduced instead of magnetovolume coupling constants, that enable us to describe all the magnetovolume properties in terms of these parameters. We have particularly found the presence of a new thermal expansion, showing T2-like temperature dependence. It explains the appreciable electronic volume thermal expansions observed experimentally. We also show that the magnetovolume coupling constants for spontaneous and forced magnetostrictions, of different magnitudes, are temperature dependent. Analysis of the pressure effect on the Curie temperature Tc and the spontaneous magnetic moment M shows that the linear relation between them, , is generally violated.
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