Prediction of high-temperature ambient-pressure superconductivity in hexagonal boron-rich clathrates

Inspired by recent predictions of superconductivity in B-C framework clathrates, we employ density functional theory to explore potential superconductors among hexagonal hydride-substituted compounds with compositions XB8C, XB7C2, XB6C3, XB3C6, XB2C7, and XBC8. Our high-throughput calculations on 96 compounds reveal several dynamically stable candidates exhibiting superconductivity at ambient pressure. An analysis of the electronic structures and electron-phonon coupling demonstrates that CaB8C, SrB8C, and BaB8C possess superconducting transition temperatures (Tc) exceeding 50 K, with CaB8C exhibiting the highest predicted Tc of 77.1 K among all stable compounds studied. These findings expand the family of B-C clathrate superconductors and provide valuable insights for experimental efforts aimed at discovering different superconducting materials. locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon Physics Subject Headings (PhySH)Density of statesFermi surfaceFirst-principles calculationsFlat bandsLattice dynamicsSuperconductivity