中国科学院物理研究所程金光团队报道了分子氢化物超导体BiH4，Tc在170GPa下高达91 K。相关研究成果发表在2024年12月23日出版的《美国化学会杂志》。

在追求高温氢化物超导体的过程中，分子氢化物引起的关注较少，因为氢准分子通常对超导性不起作用。

该文中，研究人员报告了在170-180GPa左右的压力下，成功合成新型氢化铋超导体C2/c-BiH4。它的结构由铋原子和细长的氢分子组成，在170 GPa下H-H键长度为0.81，将其表征为典型的分子氢化物。

输运测量揭示了在170 GPa下Tc高达91K时出现超导性，这可以从电阻率急剧降至零，和磁场下Tc的特征性向下偏移中得到证明。密度泛函理论的计算表明，中频H衍生声子和铋原子的低频振动，对于BiH4中的强电子-声子耦合都很重要，这使其与大多数高温超导氢化物不同。

研究工作不仅将C2/c-BiH4置于Tc最高的分子氢化物超导体之列，而且为设计和合成更多的高温氢化物超导体提供了新的方向。

附：英文原文

Title: Molecular Hydride Superconductor BiH4 with Tc up to 91 K at 170 GPa

Author: Pengfei Shan, Liang Ma, Xin Yang, Mei Li, Ziyi Liu, Jun Hou, Sheng Jiang, LiLi Zhang, Lifen Shi, Pengtao Yang, Chuanlong Lin, Bosen Wang, Jianping Sun, Haizhong Guo, Yang Ding, Huiyang Gou, Zhongxian Zhao, Jinguang Cheng

Issue&Volume: December 23, 2024

Abstract: In pursuit of high-Tc hydride superconductors, the molecular hydrides have attracted less attention because the hydrogen quasimolecules are usually inactive for superconductivity. Here, we report on the successful synthesis of a novel bismuth hydride superconductor C2/c-BiH4 at pressures around 170–180 GPa. Its structure comprises bismuth atoms and elongated hydrogen molecules with a H–H bond length of 0.81 at 170 GPa, characterizing it as a typical molecular hydride. Transport measurements revealed the occurrence of superconductivity with Tc up to 91 K at 170 GPa, as evidenced by a sharp drop of resistivity to zero and a characteristic downward shift of Tc under magnetic fields. Calculations by density functional theory elucidate that both midfrequency H-derived phonons and low-frequency vibrations from Bi atoms are important for the strong electron–phonon coupling in BiH4, differentiating it from most high-Tc superconducting hydrides. Our work not only places C2/c-BiH4 among the molecular hydride superconductors with the highest Tc but also offers new directions for designing and synthesizing more high-Tc hydride superconductors.

DOI: 10.1021/jacs.4c15137

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c15137