中国物理B ›› 2024, Vol. 33 ›› Issue (8): 86301-086301.doi: 10.1088/1674-1056/ad41b8

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First-principles study on stability and superconductivity of ternary hydride LaYHx (x =2, 3, 6 and 8)

Xiao-Zhen Yan(颜小珍)1, Xing-Zi Zhou(周幸姿)1, Chao-Fei Liu(刘超飞)1, Yin-Li Xu(徐寅力)1, Yi-Bin Huang(黄毅斌)1, Xiao-Wei Sheng(盛晓伟)2,3, and Yang-Mei Chen(陈杨梅)1,†   

  1. 1 School of Science, Jiangxi University of Science and Technology, Ganzhou 341000, China;
    2 Department of Physics, Anhui Normal University, Wuhu 241000, China;
    3 Anhui Province Key Laboratory of Optoelectric Materials Science and Technology, Wuhu 241000, China
  • 收稿日期:2024-02-25 修回日期:2024-04-22 出版日期:2024-08-15 发布日期:2024-07-15
  • 通讯作者: Yang-Mei Chen E-mail:chenyangmei@jxust.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12364003, 11804131, 11704163, 12375014, and 11875149) and the Natural Science Foundation of Jiangxi Province of China (Grant Nos. 20232BAB211022 and 20181BAB211007).

First-principles study on stability and superconductivity of ternary hydride LaYHx (x =2, 3, 6 and 8)

Xiao-Zhen Yan(颜小珍)1, Xing-Zi Zhou(周幸姿)1, Chao-Fei Liu(刘超飞)1, Yin-Li Xu(徐寅力)1, Yi-Bin Huang(黄毅斌)1, Xiao-Wei Sheng(盛晓伟)2,3, and Yang-Mei Chen(陈杨梅)1,†   

  1. 1 School of Science, Jiangxi University of Science and Technology, Ganzhou 341000, China;
    2 Department of Physics, Anhui Normal University, Wuhu 241000, China;
    3 Anhui Province Key Laboratory of Optoelectric Materials Science and Technology, Wuhu 241000, China
  • Received:2024-02-25 Revised:2024-04-22 Online:2024-08-15 Published:2024-07-15
  • Contact: Yang-Mei Chen E-mail:chenyangmei@jxust.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 12364003, 11804131, 11704163, 12375014, and 11875149) and the Natural Science Foundation of Jiangxi Province of China (Grant Nos. 20232BAB211022 and 20181BAB211007).

摘要: Recent studies have shown that the La- and Y-hydrides can exhibit significant superconducting properties under high pressures. In this paper, we investigate the stability, electronic and superconducting properties of LaYH$_{x}$ ($x=2$, 3, 6 and 8) under 0-200 GPa. It is found that LaYH$_{2}$ stabilizes in the $C2/m$ phase at ambient pressure, and transforms to the $Pmmn$ phase at 67 GPa. LaYH$_{3}$ stabilizes in the $C2/m$ phase at ambient pressure, and undergoes phase transitions of $C2/m\to P2_{1}/m\to R3m$ at 12 GPa and 87 GPa, respectively. LaYH$_{6}$ stabilizes in the $P4_{3}2_{1}2$ phase at ambient pressure, and undergoes phase transitions of $P4_{3}2_{1}2\to P4/mmm \to Cmcm$ at 28 GPa and 79 GPa, respectively. LaYH$_{8}$ stabilizes in the $Imma$ phase at 60 GPa and transforms to the $P4/mmm$ phase at 117 GPa. Calculations of the electronic band structures show that the $P4/mmm$-LaYH$_{8}$ and all phases of LaYH$_{2}$ and LaYH$_{3}$ exhibit metallic character. For the metallic phases, we then study their superconducting properties. The calculated superconducting transition temperatures ($T_{\rm c}$) are 0.47 K for $C2/m$-LaYH$_{2}$ at 0 GPa, 0 K for $C2/m$-LaYH$_{3}$ at 0 GPa, and 55.51 K for $P4/mmm$-LaYH$_{8}$ at 50 GPa.

关键词: superconductivity, high pressure, first-principles study, phase transitions

Abstract: Recent studies have shown that the La- and Y-hydrides can exhibit significant superconducting properties under high pressures. In this paper, we investigate the stability, electronic and superconducting properties of LaYH$_{x}$ ($x=2$, 3, 6 and 8) under 0-200 GPa. It is found that LaYH$_{2}$ stabilizes in the $C2/m$ phase at ambient pressure, and transforms to the $Pmmn$ phase at 67 GPa. LaYH$_{3}$ stabilizes in the $C2/m$ phase at ambient pressure, and undergoes phase transitions of $C2/m\to P2_{1}/m\to R3m$ at 12 GPa and 87 GPa, respectively. LaYH$_{6}$ stabilizes in the $P4_{3}2_{1}2$ phase at ambient pressure, and undergoes phase transitions of $P4_{3}2_{1}2\to P4/mmm \to Cmcm$ at 28 GPa and 79 GPa, respectively. LaYH$_{8}$ stabilizes in the $Imma$ phase at 60 GPa and transforms to the $P4/mmm$ phase at 117 GPa. Calculations of the electronic band structures show that the $P4/mmm$-LaYH$_{8}$ and all phases of LaYH$_{2}$ and LaYH$_{3}$ exhibit metallic character. For the metallic phases, we then study their superconducting properties. The calculated superconducting transition temperatures ($T_{\rm c}$) are 0.47 K for $C2/m$-LaYH$_{2}$ at 0 GPa, 0 K for $C2/m$-LaYH$_{3}$ at 0 GPa, and 55.51 K for $P4/mmm$-LaYH$_{8}$ at 50 GPa.

Key words: superconductivity, high pressure, first-principles study, phase transitions

中图分类号:  (Superconducting materials other than cuprates)

  • 74.70.-b
62.50.-p (High-pressure effects in solids and liquids) 63.20.dk (First-principles theory) 87.15.Zg (Phase transitions)