First-principles Study of Structural, Elastic, Anisotropic, and Thermodynamic Properties of R3-B_2C

Abstract

The structural, elastic, anisotropy, and thermodynamic properties of R3-B_2C were investigated using first-principles density functional calculations. The calculated equilibrium parameters are in good agreement with the available theoretical results. The elastic constants, elastic modulus, and elastic anisotropies of R3-B_2C were also determined in the pressure range of 0-100 GPa. The calculated elastic modulus indicates that R3-B_2C is a potential superhard material. The calculated elastic anisotropic factors suggest that R3-B2_C is elastically anisotropic. A band structure study shows that R3-B_2C is a direct semiconductor with band gap of 0.170 eV. Moreover, we predict the thermodynamic properties and obtain the relationships among the thermal expansion, temperature, and pressure, as well as the variations of the isothermal bulk modulus, Debye temperature, Gruneisen parameter, and heat capacity.