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Critical Temperature of Ferromagnetic Transition in Three-Dimensional Double-Exchange Models

Yukitoshi Motome·Nobuo Furukawa
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Abstract

Ferromagnetic transition in three-dimensional double-exchange models is studied by the Monte Carlo method. Critical temperature $T_{\rm c}$ is precisely determined by finite-size scaling analysis. Strong spin fluctuations in this itinerant system significantly reduce $T_{\rm c}$ from mean-field estimates. By choosing appropriate parameters, obtained values of $T_{\rm c}$ quantitatively agree with experiments for the ferromagnetic metal regime of (La,Sr)MnO$_{3}$, which is a typical perovskite manganite showing colossal magnetoresistance. This indicates that the double-exchange mechanism alone is sufficient to explain $T_{\rm c}$ in this material. Critical exponents are also discussed.

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Yukitoshi Motome, Nobuo Furukawa. 2000-10-20. Critical Temperature of Ferromagnetic Transition in Three-Dimensional Double-Exchange Models. https://doi.org/10.1143/jpsj.69.3785

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