Superconductivity above 200 K discovered in superhydrides of calcium

作者：Zhiwen Li, Xin He, Changling Zhang, Xiancheng Wang, Sijia Zhang, Yating Jia, Shaomin Feng, Ke Lu, Jianfa Zhao, Jun Zhang, Baosen Min, Youwen Long, Richeng Yu, Luhong Wang, Meiyan Ye, Zhanshuo Zhang, Vitali B. Prakapenka, Stella Chariton, Paul A. Ginsberg, Jay D. Bass, Shuhua Yuan, Haozhe Liu, Changqing Jin · 发表于：Nature Communications · 年份：2022 · DOI：10.1038/s41467-022-30454-w · 被引用次数：278 · 研究领域：High-pressure geophysics and materials、Superconductivity in MgB2 and Alloys、Hydrogen Storage and Materials

Abstract Searching for superconductivity with T c near room temperature is of great interest both for fundamental science & many potential applications. Here we report the experimental discovery of superconductivity with maximum critical temperature ( T c ) above 210 K in calcium superhydrides, the new alkali earth hydrides experimentally showing superconductivity above 200 K in addition to sulfur hydride & rare-earth hydride system. The materials are synthesized at the synergetic conditions of 160~190 GPa and ~2000 K using diamond anvil cell combined with in-situ laser heating technique. The superconductivity was studied through in-situ high pressure electric conductance measurements in an applied magnetic field for the sample quenched from high temperature while maintained at high pressures. The upper critical field Hc(0) was estimated to be ~268 T while the GL coherent length is ~11 Å. The in-situ synchrotron X-ray diffraction measurements suggest that the synthesized calcium hydrides are primarily composed of CaH 6 while there may also exist other calcium hydrides with different hydrogen contents.