文章基本信息

标题：Pressure-stabilized superconductive yttrium hydrides
本地全文：下载
作者：Yinwei Li ; Jian Hao ; Hanyu Liu 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
DOI：10.1038/srep09948
出版社：Springer Nature
摘要：The search for high-temperature superconductors has been focused on compounds containing a large fraction of hydrogen, such as SiH₄(H₂)₂, CaH₆ and KH₆. Through a systematic investigation of yttrium hydrides at different hydrogen contents using an structure prediction method based on the particle swarm optimization algorithm, we have predicted two new yttrium hydrides (YH₄ andYH₆), which are stable above 110 GPa. Three types of hydrogen species with increased H contents were found, monatomic H in YH₃, monatomic H+molecular “H₂” in YH₄ and hexagonal “H₆” unit in YH₆. Interestingly, H atoms in YH₆ form sodalite-like cage sublattice with centered Y atom. Electron-phonon calculations revealed the superconductive potential of YH₄ and YH₆ with estimated transition temperatures ( T _c) of 84–95 K and 251–264 K at 120 GPa, respectively. These values are higher than the predicted maximal T _c of 40 K in YH₃.