2025/12/22 by Caussé, Maélie, Bozier, Kieran, Cooke, Peter I. C. +2
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2512.19901
The discovery of high-temperature superconductors remains a central challenge in materials science. Hydrogen-rich compounds are among the most promising candidates, as they can exhibit phonon-mediated superconductivity at elevated critical temperatures, though their stabilization typically requires extreme pressures. % Here, we report the identification of YSbH6 as a promising superconductor by a multi-stage high-throughput screening on ternary A15-type hydrides, followed by a high-throughput computational search of the Y--Sb--H system, accelerated by ephemeral data derived potentials. % The cubic Pm\Bar3 YSbH6 phase exhibits a predicted critical temperature of 118 K at 50 GPa, among the highest T\rm c reported to date for an A15-hydride at this pressure. Thermodynamic analysis shows that YSbH6 lies ∼100 meV/atom above the convex hull at 50 GPa, but only 26 meV/atom above the hull at 120 GPa, suggesting possible metastability and synthesis at similar high pressure conditions. The phase is dynamically stable over a wide pressure range (20--120 GPa), displays kinetic stability at 50 GPa and elastic stability at 20 and 50 GPa, key ingredients for long-lived metastable behaviour at moderate pressures. % These results highlight YSbH6 as a benchmark case illustrating the balance between high-T\rm c performance and limited thermodynamic stability in ternary hydrides, and underscore the importance of combined dynamic, thermodynamic, kinetic and elastic stability analyses for guiding experimental synthesis of metastable superconductors.