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| Main Authors: | , , , |
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| Format: | Preprint |
| Published: |
2023
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2310.14467 |
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Table of Contents:
- Materials able to rapidly switch between thermally conductive states by external stimuli such as electric or magnetic fields can be used as all-solid-state thermal switches and open a myriad of applications in heat management, power generation and cooling. Here, we show that the large magnetoresistance that occurs in the highly conducting semimetal $α$-WSi$_{2}$ single crystals leads to dramatically large changes in thermal conductivity at temperatures <100 K. At temperatures <20 K, where electron-phonon scattering is minimized, the thermal conductivity switching ratio between zero field and a 9T applied field can be >7. We extract the electronic and lattice components of the from the thermal conductivity measurements and show that the Lorenz number for this material approximates the theoretical value of L$_{0}$. From the heat capacity and thermal diffusivity, the speed of thermal conductivity switching is estimated to range from 1 x 10$^{-4}$ seconds at 5 K to 0.2 seconds at 100 K for a 5-mm long sample. This work shows that WSi$_{2}$, a highly conducting multi-carrier semimetal, is a promising thermal switch component for low-temperature applications such cyclical adiabatic demagnetization cooling, a technique that would enable replacing $^{3}$He-based refrigerators.