Ground-state properties and hardness of high density BC6N phases originating from diamond structure

摘要

We report two possible metastable high density BC6N phases originating from the diamond structure. The ground-state properties of the BC6N phases are calculated using first-principles density-functional methods and the Vickers hardness is estimated using a semiempirical microscopic model. The calculated results show that two BC6N phases are semiconductors with Vickers hardness about 79-80 GPa, indicating that the zinc-blende-like BC6N compounds are superhard material and have larger hardness than cubic BC2N and cubic boron nitride.