Sun Ying, Zhong Xin, Liu Hanyu, Ma Yanming
Key Laboratory of Material Simulation Methods & Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China.
State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
Natl Sci Rev. 2023 Oct 31;11(7):nwad270. doi: 10.1093/nsr/nwad270. eCollection 2024 Jul.
Room-temperature superconductivity has been a long-held dream of mankind and a focus of considerable interest in the research field of superconductivity. Significant progress has recently been achieved in hydrogen-based superconductors found in superhydrides (hydrides with unexpectedly high hydrogen contents) that are stabilized under high-pressure conditions and are not capturable at ambient conditions. Of particular interest is the discovery of a class of best-ever-known superconductors in clathrate metal superhydrides that hold the record for high superconductivity (e.g. = 250-260 K for LaH) among known superconductors and have great promise to be those that realize the long-sought room-temperature superconductivity. In these peculiar clathrate superhydrides, hydrogen forms unusual 'clathrate' cages containing encaged metal atoms, of which such a kind was first reported in a calcium hexa-superhydride (CaH) showing a measured high of 215 K under a pressure of 170 GPa. In this review, we aim to offer an overview of the current status of research progress on the clathrate metal superhydride superconductors, discuss the superconducting mechanism and highlight the key features (e.g. structure motifs, bonding features, electronic structure, etc.) that govern the high-temperature superconductivity. Future research direction along this line to find room-temperature superconductors will be discussed.
室温超导一直是人类长久以来的梦想，也是超导研究领域备受关注的焦点。最近，在超氢化物（氢含量意外高的氢化物）中发现的氢基超导体取得了重大进展，这些超氢化物在高压条件下稳定，在环境条件下无法捕获。特别值得关注的是在笼形金属超氢化物中发现了一类迄今为止已知的最佳超导体——在已知超导体中，它们保持着高超导性的记录（例如，LaH的 = 250 - 260 K），并且极有希望成为实现人们长期追求的室温超导的材料。在这些特殊的笼形超氢化物中，氢形成了包含被包裹金属原子的异常“笼形”结构，其中一种首次在六超氢化钙（CaH）中报道，在170 GPa的压力下显示出测得的215 K的高 。在这篇综述中，我们旨在概述笼形金属超氢化物超导体的研究进展现状，讨论超导机制，并突出控制高温超导的关键特征（例如结构基序、键合特征、电子结构等）。还将讨论沿着这条线寻找室温超导体的未来研究方向。
