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arXiv · 1606.02010

Heat switch effect in an antiferromagnetic insulator Co$_3$V$_2$O$_8$

X. Zhao·J. C. Wu·Z. Y. Zhao·Z. Z. He·J. D. Song·J. Y. Zhao·X. G. Liu·X. F. Sun·X. G. Li
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Abstract

We report a heat switch effect in single crystals of an antiferromagnet Co$_3$V$_2$O$_8$, that is, the thermal conductivity ($κ$) can be changed with magnetic field in an extremely large scale. Due to successive magnetic phase transitions at 12--6 K, the zero-field $κ(T)$ displays a deep minimum at 6.7 K and rather small magnitude at low temperatures. Both the temperature and field dependencies of $κ$ demonstrate that the phonons are strongly scattered at the regime of magnetic phase transitions. Magnetic field can suppress magnetic scattering effect and significantly recover the phonon thermal conductivity. In particular, a 14 T field along the $a$ axis increases the $κ$ at 7.5 K up to 100 times. For $H \parallel c$, the magnitude of $κ$ can be suppressed down to $\sim$ 8% at some field-induced transition and can be enhanced up to 20 times at 14 T. The present results demonstrate that it is possible to design a kind of heat switch in the family of magnetic materials.

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X. Zhao, J. C. Wu, Z. Y. Zhao, Z. Z. He, J. D. Song, J. Y. Zhao, X. G. Liu, X. F. Sun, X. G. Li. 2016-06-07. Heat switch effect in an antiferromagnetic insulator Co$_3$V$_2$O$_8$. https://doi.org/10.1063/1.4953790

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