Wang Yanqi, Jin Yuanyuan, Yang Fulong, Zhang Jinquan, Zhang Chuanzhao, Kuang Fangguang, Ju Meng, Li Song, Cheng Shubo
Department of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, 434023, China.
School of Physics and Electronic Information, Gannan Normal University, Ganzhou, 341000, China.
Sci Rep. 2024 Jul 30;14(1):17670. doi: 10.1038/s41598-024-68697-w.
Compressed ternary alloy superhydrides are currently considered to be the most promising competitors for high-temperature superconducting materials. Here, the stable stoichiometries in the Y-Hf-H ternary system under pressure are comprehensively explored in theory and four fresh phases are predicted: Pmna-YHfH and P4/mmm-YHfH at 200 GPa, P4/mmm-YHfH at 300 GPa and P-6m2-YHfH at 400 GPa. The four Y-Hf-H ternary phases are thermodynamically and dynamically stable at corresponding pressure. In addition, structural features, bonding characteristics, electronic properties, and superconductivity of the four ternary Y-Hf-H phases are systematically calculated and discussed. As the hydrogen content and the density of states of H atoms at the Fermi level increase, the superconducting transition temperatures (T) of Y-Hf-H system are significantly enhanced. The P-6m2-YHfH with high hydrogen content exhibits a high calculated T value of 130 K at 400 GPa.
压缩三元合金超氢化物目前被认为是高温超导材料最有前景的竞争者。在此，对Y-Hf-H三元体系在压力下的稳定化学计量比进行了全面的理论探索，并预测了四个新相：200 GPa下的Pmna-YHfH和P4/mmm-YHfH、300 GPa下的P4/mmm-YHfH以及400 GPa下的P-6m2-YHfH。这四个Y-Hf-H三元相在相应压力下在热力学和动力学上是稳定的。此外，还对这四个Y-Hf-H三元相的结构特征、键合特性、电子性质和超导性进行了系统的计算和讨论。随着氢含量和费米能级处H原子的态密度增加，Y-Hf-H体系的超导转变温度（Tc）显著提高。氢含量高的P-6m2-YHfH在400 GPa下表现出高达130 K的计算Tc值。
