Phonon-mediated high-temperature superconductivity in the ternary borohydride KB2H8 under pressure near 12 GPa

Article

关键词: T-C;    PHASE;    HYDRIDE;    TRANSITION;    POTASSIUM;    LANTHANUM;   

DOI  :  10.1103/PhysRevB.104.L100504

来源: SCIE

【 摘 要 】

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 BH4 tetrahedrons into a fcc potassium lattice, KB2H8. Remarkably, we find that this material is dynamically stable and one of its sp(3)-hybridized sigma-bonding bands is metallized (i.e., partially filled) above a moderate high pressure. This metallized sigma-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.

【 授权许可】

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