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Thermal collapse of spin-polarization in half-metallic ferromagnets

M. Lezaic·Ph. Mavropoulos·J. Enkovaara·G. Bihlmayer·S. Blügel
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Abstract

The temperature dependence of the magnetization and spin-polarization at the Fermi level is investigated for half-metallic ferromagnets. We reveal a new mechanism, where the hybridization of states forming the half-metallic gap depends on thermal spin fluctuations and the polarization can drop abruptly at temperatures much lower than the Curie point. We verify this for NiMnSb by ab-initio calculations. The thermal properties are studied by mapping ab-initio results to an extended Heisenberg model which includes longitudinal fluctuations and is solved by a Monte Carlo method.

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M. Lezaic, Ph. Mavropoulos, J. Enkovaara, G. Bihlmayer, S. Blügel. 2005-12-13. Thermal collapse of spin-polarization in half-metallic ferromagnets. https://doi.org/10.1103/physrevlett.97.026404

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