Synthesis of superconducting phase of La 0.5 Ce 0.5 H 10 at high pressures

作者：Ge Huang, Di Peng, T. Luo, Liu-Cheng Chen, Philip Dalladay‐Simpson, Zi-Yu Cao, Federico A. Gorelli, Guo‐Hua Zhong, Hai-Qing Lin, Xiao‐Jia Chen · 发表于：Journal of Physics Condensed Matter · 年份：2023 · DOI：10.1088/1361-648x/ad0915 · 被引用次数：23 · 研究领域：High-pressure geophysics and materials、Rare-earth and actinide compounds、Boron and Carbon Nanomaterials Research

Abstract Clathrate hydride F m 3 ˉ m -LaH 10 has been proven as the most extraordinary superconductor with the critical temperature T c above 250 K upon compression of hundreds of GPa in recent years. A general hope is to reduce the stabilization pressure and maintain the high T c value of the specific phase in LaH 10 . However, strong structural instability distorts F m 3 ˉ m structure and leads to a rapid decrease of T c at low pressures. Here, we investigate the phase stability and superconducting behaviors of F m 3 ˉ m -LaH 10 with enhanced chemical pre-compression through partly replacing La by Ce atoms from both experiments and calculations. For explicitly characterizing the synthesized hydride, we choose lanthanum-cerium alloy with stoichiometry composition of 1:1. X-ray diffraction and Raman scattering measurements reveal the stabilization of F m 3 ˉ m -La 0.5 Ce 0.5 H 10 in the pressure range of 140–160 GPa. Superconductivity with T c of 175 ± 2 K at 155 GPa is confirmed with the observation of the zero-resistivity state and supported by the theoretical calculations. These findings provide applicability in the future explorations for a large variety of hydrogen-rich hydrides.