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arXiv · 1805.10426

Observation of gyromagnetic reversal

Masaki Imai·Yudai Ogata·Hiroyuki Chudo·Masao Ono·Kazuya Harii·Mamoru Matsuo·Yuichi Ohnuma·Sadamichi Maekawa·Eiji Saitoh
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Abstract

We report direct observation of gyromagnetic reversal, which is the sign change of gyromagnetic ratio in a ferrimagnet Ho$_3$Fe$_5$O$_{12}$, by using the Barnett effect measurement technique at low temperatures. The Barnett effect is a phenomenon in which magnetization is induced by mechanical rotation through the coupling between rotation and total angular momentum $J$ of electrons. The magnetization of Ho$_3$Fe$_5$O$_{12}$ induced by mechanical rotation disappears at 135~K and 240~K. The temperatures correspond to the magnetization compensation temperature $T_{\rm M}$ and the angular momentum compensation temperature $T_{\rm A}$, respectively. Between $T_{\rm M}$ and $T_{\rm A}$, the magnetization flips over to be parallel against the angular momentum due to the sign change of gyromagnetic ratio. This study provides an unprecedented technique to explore the gyromagnetic properties.

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Masaki Imai, Yudai Ogata, Hiroyuki Chudo, Masao Ono, Kazuya Harii, Mamoru Matsuo, Yuichi Ohnuma, Sadamichi Maekawa, Eiji Saitoh. 2018-08-02. Observation of gyromagnetic reversal. https://doi.org/10.1063/1.5041464

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