Abstract
Abstract
Clathrate hydride
F
m
3
ˉ
m
-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
F
m
3
ˉ
m
structure and leads to a rapid decrease of Tc
at low pressures. Here, we investigate the phase stability and superconducting behaviors of
F
m
3
ˉ
m
-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
F
m
3
ˉ
m
-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.
Funder
Key R&D Program of China
Shenzhen Science and Technology Program
National Natural Science Foundation of China
Basic Research Program of Shenzhen
Subject
Condensed Matter Physics,General Materials Science