Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015.
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853.
Proc Natl Acad Sci U S A. 2017 Jul 3;114(27):6990-6995. doi: 10.1073/pnas.1704505114. Epub 2017 Jun 19.
A systematic structure search in the La-H and Y-H systems under pressure reveals some hydrogen-rich structures with intriguing electronic properties. For example, LaH is found to adopt a sodalite-like face-centered cubic (fcc) structure, stable above 200 GPa, and LaH a 2/ space group structure. Phonon calculations indicate both are dynamically stable; electron phonon calculations coupled to Bardeen-Cooper-Schrieffer (BCS) arguments indicate they might be high- superconductors. In particular, the superconducting transition temperature calculated for LaH is 274-286 K at 210 GPa. Similar calculations for the Y-H system predict stability of the sodalite-like fcc YH and a above room temperature, reaching 305-326 K at 250 GPa. The study suggests that dense hydrides consisting of these and related hydrogen polyhedral networks may represent new classes of potential very high-temperature superconductors.
在 La-H 和 Y-H 体系中的系统结构搜索揭示了一些具有有趣电子性质的富氢结构。例如，LaH 被发现采用类似于方钠石的面心立方 (fcc) 结构，在 200 GPa 以上稳定，而 LaH a 2/空间群结构。声子计算表明它们都是动力学稳定的；电子声子计算与 Bardeen-Cooper-Schrieffer (BCS) 论点相结合表明它们可能是高温超导体。特别是，对于 LaH，在 210 GPa 时计算出的超导转变温度 为 274-286 K。对 Y-H 体系的类似计算预测了类似于方钠石的 fcc YH 和 在室温以上的稳定性，在 250 GPa 时达到 305-326 K。该研究表明，由这些和相关的氢多面体网络组成的高密度氢化物可能代表新的潜在高温超导体类别。
