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arXiv · 2304.14728

Glass-like Cross-plane Thermal Conductivity of Kagome Metals RbV3Sb5 and CsV3Sb5

Yu Pang·Jinjin Liu·Zeyu Xiang·Xuanhui Fan·Jie Zhu·Zhiwei Wang·Yugui Yao·Xin Qian·Ronggui Yang
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Abstract

This work reports the thermal conductivity of RbV3Sb5 and CsV3Sb5 with three-dimensional charge density wave phase transitions from 80 K to 400 K measured by pump-probe thermoreflectance techniques. The in-plane (basal plane) thermal conductivities are found moderate, i.e., 12 W/mK of RbV3Sb5 and 8.8 W/mK of CsV3Sb5 at 300 K. Low cross-plane (stacking direction) thermal conductivities are observed, with 0.72 W/mK of RbV3Sb5 and 0.49 W/mK of CsV3Sb5 at 300 K. A unique glass-like temperature dependence in the cross-plane thermal conductivity is observed, which decreases monotonically even lower than the Cahill-Pohl limit as the temperature decreases below the phase transition point TCDW. This temperature dependence is found to obey the hopping transport picture. In addition, a peak in cross-plane thermal conductivity is observed at TCDW as a fingerprint of the modulated structural distortion along the stacking direction.

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Yu Pang, Jinjin Liu, Zeyu Xiang, Xuanhui Fan, Jie Zhu, Zhiwei Wang, Yugui Yao, Xin Qian, Ronggui Yang. 2023-04-28. Glass-like Cross-plane Thermal Conductivity of Kagome Metals RbV3Sb5 and CsV3Sb5. https://doi.org/10.1103/physrevb.108.205112

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