Mechanical and thermodynamic properties of cubic boron nitride from ab initio calculation

Ab initio calculation shows that the ideal strength of C-BN phase in the [111] direction has lower values, which signifies first cleave in the (111) plane under tensile loadings. It is found that C-BN phase possesses a stronger covalent bonding and wide bandgap. In addition, a combination of first principles calculation and quasi-harmonic Debye model are extremely useful in studying thermodynamic and elastic properties of C-BN phase within the temperature range of 0-2000 K. The calculated results are in good agreements with experimental observations in the literature, and are discussed in terms of electronic structures, heat of information and ideal strength.