Z-BN: a novel superhard boron nitride phase.
A superhard boron nitride phase dubbed as Z-BN is proposed as a possible intermediate phase between h-BN and zinc blende BN (c-BN), and investigated using first-principles calculations within the framework of density functional theory. Although the structure of Z-BN is similar to that of bct-BN containing four-eight BN rings, it is more energetically 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 an indirect band gap of 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.
Laboratory for Quantum Engineering and Micro-Nano Energy Technology, Xiangtan University, Xiangtan 411105, China.
Chaoyu
C
He
Lizhong
L
Sun
Chunxiao
C
Zhang
Xiangyang
X
Peng
Kaiwang
K
Zhang
Jianxin
J
Zhong