Inspired by the high critical temperature in yttrium superhydride and the low stabilized pressure in superconducting cerium superhydride, we carry out four independent runs to synthesize yttrium-cerium alloy hydrides. The phases examined by the Raman scattering and x-ray diffraction measurements. The superconductivity is detected with the zero-resistance state at the critical temperature in the range of 97-140 K at pressures ranging from 114 GPa to 120±4 GPa. The maximum critical temperature of the synthesized hydrides is larger than those reported for cerium hydrides, while the corresponding stabilized pressure is much lower than those for superconducting yttrium hydrides. The structural analysis and theoretical calculations suggest that the phase of Y0.5Ce0.5H9 has the space group P63/mmc with the calculated critical temperature of 119 K, in fair agreement with the experiments. These results indicate that alloying superhydrides indeed can maintain relatively high critical temperature at modest pressures accessible by many laboratories.
@article{arxiv.2208.05191,
title = {Synthesis and Superconductivity in Yttrium-Cerium Hydrides at Moderate Pressures},
author = {Liu-Cheng Chen and Tao Luo and Philip Dalladay-Simpson and Ge Huang and Zi-Yu Cao and Di Peng and Federico Aiace Gorelli and Guo-Hua Zhong and Hai-Qing Lin and Xiao-Jia Chen},
journal= {arXiv preprint arXiv:2208.05191},
year = {2022}
}