摘要
High superconducting critical temperature of 73.6 K at ambient pressure is predicted in BSiC 2 by means of the first-principles electron-phonon calculations. Without the need for doping or pressurization, the stoichiometric BSiC 2 exhibits strong electron-phonon coupling (EPC) and highest among BCS-superconductors at ambient pressure. Also, it is hydrogen-free that makes easier the sample growth. The dramatic softening of the mode is the main account for the strong EPC. In addition, we find that BC 3 , derived from the replacement of Si in BSiC 2 by another C, is also superconducting with a high 40 K. Our work indicates that these materials form a new family of high- BCS-superconductors at ambient pressure.