First-principles study of cubic BC6N: Structural forms and ideal strength

We present first-principles calculations on the structural forms and ideal strength of cubic BC6N. The calculated ideal tensile and shear strength are lower or comparable to those of c-BN. Our results show that increasing carbon content does not lead to significant enhancement of the idea strength as expected by the conventional wisdom. It can be attributed to the weak C-N bonds that impose a limit on the idea strength.