Superhard and superconductive nondiamond-like BC structure

Authors：Li, Penghui; Hao, Lingjuan; Li, Baozhong; Zhang, Shuangshuang; Wu, Yingju; Xiong, Mei; Huang, Quan; Zhao, Zhisheng; Chen, Junyun; Ma, Mengdong^*; He, Julong^*

Source：Diamond and Related Materials, 2020, 110: 108142.

DOI：10.1016/j.diamond.2020.108142

• B-C compounds
• Superhard
• Superconductivity
• Electronic properties
• Structural properties

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 t(2)-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 t(2)-BC is superhard (H-v = 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.

• Institution
  Yanshan University