2022/08/10 by Ge Huang, Huang, Ge, T. Luo +17
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Chemical Physics Studies #FOS: Physical sciences #High-pressure geophysics and materials #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2208.05199
openalex publication_date 2022/08/10 · openalex created_date 2022/08/12 · openalex updated_date 2026/07/28
Clathrate hydride Fm\=3m-LaH10 has been proven as the most extraordinary superconductor with the critical temperature Tc 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 Tc value of the specific phase in LaH10. However, strong structural instability distorts Fm\=3m structure and leads to a rapid decrease of Tc at low pressures. Here, we investigate the phase stability and superconducting behaviors of Fm\=3m-LaH10 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 Fm\=3m-La0.5Ce0.5H10 in the pressure range of 140-160 GPa. Superconductivity with Tc 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.