CURIE TEMPERATURE AND BAND STRUCTURE OF METALLIC FERROMAGNETS
- Resource Type
- Authors
- X.-L. Rao; J. M. D. Coey; Qinian Qi; Ralph Skomski
- Source
- Journal of the Magnetics Society of Japan. 19:S1_193-196
- Subject
- Materials science
Curie–Weiss law
Condensed matter physics
Heisenberg model
Classical Heisenberg model
Condensed Matter Physics
Electronic, Optical and Magnetic Materials
Condensed Matter::Materials Science
Paramagnetism
Curie's law
Ferromagnetism
Curie temperature
Condensed Matter::Strongly Correlated Electrons
Curie constant
Electrical and Electronic Engineering
Instrumentation
- Language
- ISSN
- 1880-4004
0285-0192
A soft-spin Heisenberg model is used to investigate the Curie temperature of elementary iron and iron-rich intermetallics such as Sm2Fe17. In the localized limit the mean-field solution of the classical Heisenberg model is reproduced, while quasi-localized perturbation theory accounts for band-structure effects. An extrapolation of this quasi-localized approach yields physically reasonable results, which makes it possible to interpolate between the delocalized band-structure and localized Heisenberg limits. Using Stoner-type magnetic energies derived from paramagnetic band-structure calculations it is argued that the comparatively low Curie temperature of iron-rich rare-earth intermetallics such as R2Fe17 originates from their quasi-weak ferromagnetism. Upon interstitial modification, these materials leave the quasi-weak limit and become nearly strong ferromagnets with enhanced Curie temperature.