Abstract Diamond-like B-C compounds exhibit the favorable properties of high hardness and superconductivity. The explorations for novel B-C phases are kept on going and it was desirable to explore whether the diamond-like structure can still exist stably or not when the content of boron increases. Herein we predicted a nondiamond-like structure t2-BC took place the lowest energy position of the diamond-like structure, which is completely different from the BCx (x ≥ 2) system. Based on elastic constants and phonon dispersion calculations, the mechanical and dynamic stability of t2-BC were confirmed. Furthermore, hardness and electron–phonon calculations reveal that t2-BC is superhard (Hv = 55.4 GPa) and superconductive with superconducting critical temperature reaching 6.4 K. These results have practical significance for the experimental synthesis of diamond and nondiamond like B-C compounds.

中文翻译：

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超硬超导非类金刚石BC结构

摘要 类金刚石BC化合物具有高硬度和超导电性等优良特性。对新型 BC 相的探索仍在继续，希望探索当硼含量增加时类金刚石结构是否仍能稳定存在。在此我们预测了非类金刚石结构 t2-BC 发生在类金刚石结构的最低能量位置，这与 BCx (x ≥ 2) 系统完全不同。基于弹性常数和声子色散计算，证实了 t2-BC 的机械和动态稳定性。此外，硬度和电子-声子计算表明 t2-BC 是超硬（Hv = 55.4 GPa）和超导的，超导临界温度达到 6.4 K。