Key Laboratory of Applied Chemistry, Yanshan University, Qinhuangdao, China.
Phys Chem Chem Phys. 2012 Jan 14;14(2):869-76. doi: 10.1039/c1cp22914a. Epub 2011 Nov 29.
First-principle calculations of the structural, electronic, vibrational and mechanical properties of the primitive-centered tetragonal boron nitride (pct-BN) structure are performed. Results reveal that pct-BN is more energetically favorable than h-BN above the pressure of 8.8 GPa and dynamically stable at up to 120 GPa. Electronic bonding indicates that pct-BN possesses a covalent character with near-tetrahedral sp(3)-hybridized electronic states. Vibrational property calculations show that its characteristic sp(3) Raman peaks are at 738 cm(-1), 1032 cm(-1) and 1155 cm(-1). The mechanical failure mode of pct-BN is dominated by the shear type. The lowest peak stress of 43.1 GPa under (110) [11(-)0] shear sets an upper bound for its ideal strength. The calculated minimum hardness of pct-BN is greater than that of w-BN. Its average hardness approached that of c-BN, indicating that this novel BN allotrope is a potential superhard material.
采用第一性原理计算方法研究了原始中心四方氮化硼（pct-BN）结构的结构、电子、振动和力学性能。结果表明，pct-BN 在 8.8GPa 以上的压力下比 h-BN 更具能量优势，在高达 120GPa 的压力下是动力学稳定的。电子键合表明，pct-BN 具有近四面体 sp(3)-杂化的电子态的共价性质。振动特性计算表明，其特征 sp(3)拉曼峰位于 738cm(-1)、1032cm(-1)和 1155cm(-1)处。pct-BN 的机械失效模式主要是剪切型。在（110）[11(-)0]剪切下的最低峰值应力 43.1GPa 为其理想强度设定了上限。计算得到的 pct-BN 的最小硬度大于 w-BN。其平均硬度接近 c-BN，表明这种新型 BN 同素异形体是一种潜在的超硬材料。
