Crystal Structure of the Superconducting Phase of Sulfur Hydride.
Crystal Structure of the Superconducting Phase of Sulfur Hydride.
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DOI：
10.1038/nphys3760
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发表时间：
2016-09
期刊：
影响因子：
19.6
通讯作者：
Ohishi Y
中科院分区：
文献类型：
--
作者：
Einaga M;Sakata M;Ishikawa T;Shimizu K;Eremets MI;Drozdov AP;Troyan IA;Hirao N;Ohishi Y
最近在高静水压力下发现H2S（或D2S）的超导临界温度高于200 K。这些测量结果被解释为这些材料分解成元素硫和富氢氢化物，这是负责超导性，尽管这种机制的直接实验证据迄今为止还缺乏。在这里，我们报告的超导相的硫化氢（和硫化氘）在正常和超导状态的晶体结构，通过同步辐射X射线衍射测量，结合在室温和低温下的电阻测量。我们发现超导相与理论预测的H3S的体心立方（bcc）结构基本一致。元素硫的存在在X射线衍射图中也是明显的，从而证明了H2S在压力下分解为H3S + S的机理。
A superconducting critical temperature above 200 K has recently been discovered in H2S (or D2S) under high hydrostatic pressure. These measurements were interpreted in terms of a decomposition of these materials into elemental sulfur and a hydrogen-rich hydride that is responsible for the superconductivity, although direct experimental evidence for this mechanism has so far been lacking. Here we report the crystal structure of the superconducting phase of hydrogen sulfide (and deuterium sulfide) in the normal and superconducting states obtained by means of synchrotron X-ray diffraction measurements, combined with electrical resistance measurements at both room and low temperatures. We find that the superconducting phase is mostly in good agreement with theoretically predicted body-centered cubic (bcc) structure for H3S (Ref.). The presence of elemental sulfur is also manifest in the X-ray diffraction patterns, thus proving the decomposition mechanism of H2S to H3S + S under pressure.