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arXiv 2105.06352cond-mat.supr-concond-mat.mtrl-sci
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C-S-H室温超导体的X射线衍射和物态方程

X-ray Diffraction and Equation of State of the C-S-H Room-Temperature Superconductor

Anmol Lamichhane, Ravhi Kumar, Muhtar Ahart, Nilesh P. Salke, Nathan Dasenbrock-Gammon, Elliot Snider, Yue Meng, Barbara Lavina, Stella Chariton, Vitali B. Prak… 展开作者

Anmol Lamichhane, Ravhi Kumar, Muhtar Ahart, Nilesh P. Salke, Nathan Dasenbrock-Gammon, Elliot Snider, Yue Meng, Barbara Lavina, Stella Chariton, Vitali B. Prakapenka, Maddury Somayazulu, Ranga P. Dias, Russell J. Hemley

摘要:

X射线衍射表明,最近发现的室温碳质硫氢化物(C-S-H)超导体的结构是由先前在H $_2$ S-H $_2$和CH $_4$ -H $_2$系统中发现的范德华化合物衍生而来的。通过光化学合成技术产生超导相的晶体,导致在267 GPa下超导临界温度$T_c$为288 K。单晶X射线衍射图在超导相的压力范围内,从124到178 GPa测量,给出了由Al $_2$ Cu型确定的正交结构,(H $_2$ S)$_2$ H $_2$和(CH $_4$)$_2$ H $_2$,与S-H系统对这些压力。C-S-H化合物的形成和稳定性可以根据H $_2$ S和CH $_4$组分在宽压力范围内的有效体积的密切相似性来理解。结构中碳和硫的相对量是不确定的,并且更致密的含碳S-H结构可以在更高的压力下形成。这一结果与碳对$T_c$的空穴掺杂增强作用一致。

英文摘要:

X-ray diffraction indicates that the structure of the recently discovered room temperature carbonaceous sulfur hydride (C-S-H) superconductor is derived from previously established van der Waals compounds found in the H$_2$S-H$_2$ and CH$_4$-H$_2$ systems. Crystals of the superconducting phase were produced by a photochemical synthesis technique leading to the superconducting critical temperature $T_c$ of 288 K at 267 GPa. Single-crystal x-ray diffraction patterns measured from 124 to 178 GPa, within the pressure range of the superconducting phase, give an orthorhombic structure derived from the Al$_2$Cu-type determined for (H$_2$S)$_2$H$_2$ and (CH$_4$)$_2$H$_2$ that differs from those predicted and observed for the S-H system to these pressures. The formation and stability of the C-S-H compound can be understood in terms of the close similarity in effective volumes of the H$_2$S and CH$_4$ components over a broad range of pressures. The relative amounts of carbon and sulfur in the structure is not determined, and denser carbon-bearing S-H structures may form at higher pressures. The results are consistent with hole-doping enhancement of $T_c$ by carbon proposed for the room-temperature superconductivity in this system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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