通过广泛的计算搜索，该研究团队预测了一类独特的热力学稳定的笼型氢化物结构，包括两个以前未报道的兆巴压力下的H24和H30笼型氢笼。在这些相中，LaSc2H24在167至300 GPa的热力学稳定压力范围内展现出潜在的热超导性。特别地，在250 GPa时，其超导临界温度（Tcs）高达331 K，而在167 GPa时，Tcs也能达到316 K，这其中非谐性效应起到了关键的作用。极高的临界温度源于新发现的奇特的H30和H24笼结构，在费米能级上产生了异常丰富的氢衍生电子态密度。研究人员预测，在La-H体系中引入Sc将有利于未来三元笼型超氢化物中热超导体的设计与实现。
据悉，最近由理论驱动的一类笼型氢化物(例如，CaH6, YH6, YH9和LaH10)的超导临界温度(Tc)远高于200 K的发现，为室温以上压力下的“热”超导开辟了前景。最近的努力集中在三元氢化物中寻找超导体，与二元氢化物相比，三元氢化物可以容纳更多不同的材料类型和结构。
附：英文原文
Title: Predicted hot superconductivity in LaSc2H24 under pressure
Author: He, Xin-Ling, Zhao, Wenbo, Xie, Yu, Hermann, Andreas, Hemley, Russell J., Liu, Hanyu, Ma, Yanming
Issue&Volume: 2024-6-20
Abstract: The recent theory-driven discovery of a class of clathrate hydrides (e.g., CaH6, YH6, YH9, and LaH10) with superconducting critical temperatures (Tc) well above 200 K has opened the prospects for “hot” superconductivity above room temperature under pressure. Recent efforts focus on the search for superconductors among ternary hydrides that accommodate more diverse material types and configurations compared to binary hydrides. Through extensive computational searches, we report the prediction of a unique class of thermodynamically stable clathrate hydrides structures consisting of two previously unreported H24 and H30 hydrogen clathrate cages at megabar pressures. Among these phases, LaSc2H24 shows potential hot superconductivity at the thermodynamically stable pressure range of 167 to 300 GPa, with calculated Tcs up to 331 K at 250 GPa and 316 K at 167 GPa when the important effects of anharmonicity are included. The very high critical temperatures are attributed to an unusually large hydrogen-derived density of states at the Fermi level arising from the newly reported peculiar H30 as well as H24 cages in the structure. Our predicted introduction of Sc in the La–H system is expected to facilitate future design and realization of hot superconductors in ternary clathrate superhydrides.
DOI: 10.1073/pnas.2401840121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2401840121