1204.2188 (Chaoyu He et al.)

First-principles study of a novel superhard boron nitride phase    [PDF]

Chaoyu He, L. Z. Sun, C. X. Zhang, Xiangyang Peng, K. W. Zhang, Jianxin Zhong

A superhard boron nitride phase dubbed as Z-BN is proposed as possible intermediate phase between h-BN and zinc blende BN (c-BN), and investigated using first-principles calculations within the framework of the density functional theory. Although the structure of Z-BN is similar to that of bct-BN containing four-eight BN rings, it is more energy favorable than bct-BN. Our study reveals that Z-BN, with a considerable structural stability and high density comparable to c-BN, is a transparent insulator with a indirect band gap about 5.27 eV. Amazingly, its Vickers hardness is 55.88 Gpa which is comparable to that of c-BN. This new BN phase may be produced in experiments through cold compressing AB stacking h-BN due to its low transition pressure point of 3.3 GPa.

View original: http://arxiv.org/abs/1204.2188