Body-centered superhard BC2N phases from first principles
Body-centered superhard BC2N phases from first principles
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DOI：
10.1103/physrevb.76.094103
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发表时间：
2007-09
影响因子：
3.7
通讯作者：
Xiaoguang Luo;Xiaoju Guo;Bo Xu;Qinghua Wu;Qianku Hu;Zhongyuan Liu;Julong He;D. Yu;Yongjun Tian;Hui-Tian Wang
中科院分区：
文献类型：
--
作者：
Xiaoguang Luo;Xiaoju Guo;Bo Xu;Qinghua Wu;Qianku Hu;Zhongyuan Liu;Julong He;D. Yu;Yongjun Tian;Hui-Tian Wang
体心 $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ 由最近预测的体心碳晶胞推导出来 [F. J. Ribeiro 等人，物理学。 Rev. B 74, 172101 (2006)]用第一原理赝势密度泛函方法进行了研究。研究了体心 $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ 11 种可能的原子构型的结构、电子和机械特性。我们的结果表明，$s{p}^{3}$键合的体心$\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$相的密度低于之前研究的$s{p}^{3}$键合的闪锌矿$\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$、纤锌矿$\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ 和黄铜矿 $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$。在所研究的体心 $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ 结构中，由最多数量的 C-C 和 B-N 键组成的 struc-A 和 struc-B 具有最低的总能量。他们计算出的体积模量分别为 305 和 $309\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$。体心$\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$的理论维氏硬度超过$60\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$，表明它是一种潜在的超硬材料，硬度与立方氮化硼相当。
Body-centered $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ deduced from the unit cell of the recently predicted body-centered carbon [F. J. Ribeiro et al., Phys. Rev. B 74, 172101 (2006)] are studied with first-principles pseudopotential density functional method. The structural, electronic, and mechanical properties are investigated for 11 possible atomic configurations of body-centered $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$. Our results show that the $s{p}^{3}$-bonded body-centered $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ phases have lower density than the previously investigated $s{p}^{3}$-bonded zinc-blende $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$, wurtzite $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$, and chalcopyrite $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$. The struc-A and struc-B composed of the maximum numbers of C-C and B-N bonds have the lowest total energy among the investigated body-centered $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ structures. Their calculated bulk moduli are 305 and $309\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, respectively. The theoretical Vickers hardness of the body-centered $\mathrm{B}{\mathrm{C}}_{2}\mathrm{N}$ is over $60\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, indicating that it is a potential superhard material with the hardness comparable to cubic boron nitride.