The binary polyhydrides of heavy rare earth lutetium that shares a similar valence electron configuration to lanthanum have been experimentally discovered to be superconductive. The lutetium polyhydrides were successfully synthesized at high pressure and high temperature conditions using a diamond anvil cell in combinations with the in-situ high pressure laser heating technique. The resistance measurements as a function of temperature were performed at the same pressure of synthesis in order to study the transitions of superconductivity (SC). The superconducting transition with a maximum onset temperature (Tc) 71 K was observed at pressure of 218 GPa in the experiments. The Tc decreased to 65 K when pressure was at 181 GPa. From the evolution of SC at applied magnetic fields, the upper critical field at zero temperature {\mu}0Hc2(0) was obtained to be ~36 Tesla. The in-situ high pressure X-ray diffraction experiments imply that the high Tc SC should arise from the Lu4H23 phase with Pm-3n symmetry that forms a new type of hydrogen cage framework different from those reported for previous light rare earth polyhydride superconductors.
@article{arxiv.2303.05117,
title = {Superconductivity above 70 K observed in lutetium polyhydrides},
author = {Zhiwen Li and Xin He and Changling Zhang and Ke Lu and Baosen Min and Jun Zhang and Sijia Zhang and Jianfa Zhao and Luchuan Shi and Shaomin Feng and Xiancheng Wang and Yi Peng and Richeng Yu and Luhong Wang and Yingzhe Li and Jay D Bass and Vitali Prakapenka and Stella Chariton and Haozhe Liu and Changqing Jin},
journal= {arXiv preprint arXiv:2303.05117},
year = {2023}
}