Abstract
The discovery of high-temperature superconductivity in hydrogen-rich compounds has fueled the enthusiasm for finding materials with more promising superconducting properties among hydrides. However, the ultrahigh pressure needed to synthesize and maintain high-temperature hydrogen-rich superconductors hinders the experimental investigation of these materials. For practical applications, it is also highly desired to find more hydrogen-rich materials that superconduct at high temperatures but under relatively lower pressures. Based on first-principles density functional theory, we calculate the electronic and phonon band structures for a ternary borohydride formed by intercalating tetrahedrons into a fcc potassium lattice, . Remarkably, we find that this material is dynamically stable and one of its -hybridized -bonding bands is metallized (i.e., partially filled) above a moderate high pressure. This metallized -bonding band couples strongly with phonons, giving rise to a strong superconducting pairing potential. By solving the anisotropic Eliashberg equations, we predict that the superconducting transition temperature of this compound is 134–146 K around 12 GPa.
- Received 23 June 2021
- Accepted 7 September 2021
DOI:https://doi.org/10.1103/PhysRevB.104.L100504
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