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arXiv · 2104.13994

Thermal diffusivity and its lower bound in orthorhombic SnSe

Valentina Martelli·Fabio Abud·Julio Larrea Jiménez·Elisa Baggio-Saitovich·Li-Dong Zhao·Kamran Behnia
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Abstract

The orthorhombic monochalcogenide SnSe has attracted much attention in recent years as a promising high-temperature thermoelectric material. We present a study of its thermal conductivity and specific heat of SnSe between 2~K and 300~K and quantify its anisotropic thermal diffusivity, $D$. For both crystallographic orientations, thermal diffusivity remains above the recently identified Planckian limit ($D > v_s^2 \tau_P$, where $v_s$ is the sound velocity and $\tau_P= \hbar/k_BT$) and its anisotropy in $D$ is set by the anisotropy of $v_s$. Comparison with cubic members of the IV-VI family leads to a consistent picture, where the diffusivity in all members of the family is set by the product of v$_s$, $\tau_P$ and the 'melting' velocity derived from the melting temperature.

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Valentina Martelli, Fabio Abud, Julio Larrea Jiménez, Elisa Baggio-Saitovich, Li-Dong Zhao, Kamran Behnia. 2021-04-28. Thermal diffusivity and its lower bound in orthorhombic SnSe. https://doi.org/10.1103/physrevb.104.035208

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