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arXiv · 2505.09195

Study of magneto-thermal resistance effect in a Co50Fe50/Cu multilayer through the analysis of electron and lattice thermal conductivities

Fuya Makino·Takamasa Hirai·Takuma Shiga·Hirofumi Suto·Hiroshi Fujihisa·Koichi Oyanagi·Satoru Kobayashi·Taisuke Sasaki·Takashi Yagi·Ken-ichi Uchida·Yuya Sakuraba
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Abstract

This study investigates the giant magneto-thermal resistance (GMTR) effect in a fully-bcc epitaxial Co50Fe50/Cu multilayer through both experimental and theoretical approaches. The applied magnetic field results in a giant change of the cross-plane thermal conductivity ({\Delta}\k{appa}) of 37 W m-1 K-1, which reaches 1.5 times larger than the previously reported value for a magnetic multilayer and record the highest value at room temperature among the other solid-state thermal switching materials working on different principles. We investigated the electron thermal conductivity for exploring the remarkable {\Delta}\k{appa} by the two-current-series-resistor model combined with the Wiedemann-Franz (WF) law. However, the result shows the electron contribution accounts for only 35% of the {\Delta}\k{appa}, indicating the presence of additional spin-dependent heat carriers. Further investigation of the lattice thermal conductivity, which is expected to be spin-independent, using non-equilibrium molecular dynamics (NEMD) simulations suggests a striking contrast: the additional spin-dependent heat carrier contribution is significantly enhanced in the parallel magnetization configuration but nearly negligible in the antiparallel configuration. These findings provide a fundamental insight into the origin of large GMTR effect and highlight its potential of active thermal management technologies for future electronic devices.

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Fuya Makino, Takamasa Hirai, Takuma Shiga, Hirofumi Suto, Hiroshi Fujihisa, Koichi Oyanagi, Satoru Kobayashi, Taisuke Sasaki, Takashi Yagi, Ken-ichi Uchida, Yuya Sakuraba. 2025-05-14. Study of magneto-thermal resistance effect in a Co50Fe50/Cu multilayer through the analysis of electron and lattice thermal conductivities. https://arxiv.org/abs/2505.09195

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