The energetics of defects in B 4+xC boron carbide and β-boron are studied through first-principles calculations, the supercell phonon approach and the Debye-Grüneisen model. It is found that suitable sublattice models for β-boron and B 4+xC are B 101(B,C) 4 and B 11(B,C) (B,C,Va) (B,Va) (B,C,Va), respectively. The thermodynamic properties of B 4+xC, β-boron, liquid and graphite are modeled using the CALPHAD approach based on the thermochemical data from first-principles calculations and experimental phase equilibrium data in the literature. The concentrations of various defects are then predicted as a function of carbon composition and temperature.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys