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arXiv · 2209.05014

Phase Transitions and Superconductivity in Ternary Hydride Li$_2$SiH$_6$ at High Pressures

Sixuan Wu·Bin Li·Zhi Chen·Yu Hou·Yan Bai·Xiaofeng Hao·Yeqian Yang·Shengli Liu·Jie Cheng·Zhixiang Shi
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Abstract

We predicted a new ternary hydride Li$_2$SiH$_6$ at high pressures. A systematic structure search in Li$_2$SiH$_6$ compound reveals novel stable phases with intriguing electronic and phonon properties. It is found that Li$_2$SiH$_6$ is dynamically stable from ambient pressure up to 400 GPa with three novel phases: P312, P$\bar{3}$, and P$\bar{6}$2m. The calculation of electron-phonon coupling combined with Bardeen-Cooper-Schrieffer's argument indicates that this compound may be a candidate for high $T_c$ superconductors under high pressures. In particular, the maximum $T_c$ of $P\bar{6}2m$-Li$_2$SiH$_6$ at 400 GPa reaches 56 K. These findings may pave the way for obtaining room temperature superconductors in dense hydrogen-rich compounds.

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Sixuan Wu, Bin Li, Zhi Chen, Yu Hou, Yan Bai, Xiaofeng Hao, Yeqian Yang, Shengli Liu, Jie Cheng, Zhixiang Shi. 2022-09-12. Phase Transitions and Superconductivity in Ternary Hydride Li$_2$SiH$_6$ at High Pressures. https://doi.org/10.1063/5.0080880

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