Novel carbon-rich B-C compounds in orthorhombic phase: First-principles calculations

A novel carbon-rich B-C compounds B2C3 in orthorhombic phase is proposed in this work. Firstly, the stability of B2C3 has been demonstrated, the thermodynamic stability, dynamic stability, and mechanical stability of B2C3 are confirmed by the formation enthalpies, phonon spectra and elastic constants, respectively. As a semiconductor material with indirect band gap, B2C3 has a larger mechanical anisotropy in Poisson's ratio, Young's modulus, and shear modulus by three-dimensional distribution and two-dimensional representation, while in some main planes, the mechanical anisotropy in Poisson's ratio, Young's modulus, and shear modulus of B2C3 are slightly smaller than that of other B-C compounds. In addition, B2C3 shows negative Poisson's ratio in (111), (100), (010), and (001) planes, which can supply more potential areas to be used than other boron carbide compounds.