Design of High-Temperature Superconducting Ternary Hydride NaY3H20 at Moderate Pressure via Introducing Hydrogen
Decheng An1, Wendi Zhao1, Qiwen Jiang1
1State Key Laboratory of Superhard Materials and Key Laboratory of Material Simulation Methods & Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China.
Abstract:
Superconducting hydrides exhibiting a high critical temperature (Tc) under extreme pressures have garnered significant interest. However, the extremely high pressures required for their stability have limited their practical applications. The current challenge is to identify high-Tc superconducting hydrides that can be stabilized at lower or even ambient pressures. Here, we propose a strategy for designing high-Tc superconducting hydrides at low pressures by introducing defects into the hydrogen frameworks of clathrate hydrides. We present a type of hydrogen-vacancy structural type AB3H20 derived from type-I clathrate hydrides and identified a stable NaY3H20 through high-throughput calculations. Further calculations show that NaY3H20 is thermodynamically stable above 133 GPa and dynamically stable down to 20 GPa, with a predicted high Tc of approximately 115 K. It significantly reduces the pressure required for stability compared to that of type-I clathrate hydrides with high Tc. Our results provide a foundation for further exploration of high-Tc superconducting hydrides at lower pressures or even ambient conditions.
