Xing Mengjiang, Li Binhua, Yu Zhengtao, Chen Qi
Faculty of Information Engineering and Automation, Kunming University of Science and Technology, Kunming 650051, China.
Materials (Basel). 2016 Jun 17;9(6):484. doi: 10.3390/ma9060484.
I 4 ¯ -carbon was first proposed by Zhang et al., this paper will report regarding this phase of carbon. The present paper reports the structural and elastic properties of the three-dimensional carbon allotrope I 4 ¯ -carbon using first-principles density functional theory. The related enthalpy, elastic constants, and phonon spectra confirm that the newly-predicted I 4 ¯ -carbon is thermodynamically, mechanically, and dynamically stable. The calculated mechanical properties indicate that I 4 ¯ -carbon has a larger bulk modulus (393 GPa), shear modulus (421 GPa), Young's modulus (931 GPa), and hardness (55.5 GPa), all of which are all slightly larger than those of c-BN. The present results indicate that I 4 ¯ -carbon is a superhard material and an indirect-band-gap semiconductor. Moreover, I 4 ¯ -carbon shows a smaller elastic anisotropy in its linear bulk modulus, shear anisotropic factors, universal anisotropic index, and Young's modulus.
I4̅-碳最初由张等人提出，本文将报道关于这一碳相的内容。本文使用第一性原理密度泛函理论报道了三维碳同素异形体I4̅-碳的结构和弹性性质。相关的焓、弹性常数和声子谱证实，新预测的I4̅-碳在热力学、力学和动力学上是稳定的。计算得到的力学性能表明，I4̅-碳具有较大的体模量（393吉帕）、剪切模量（421吉帕）、杨氏模量（931吉帕）和硬度（55.5吉帕），所有这些都略大于立方氮化硼。目前的结果表明，I4̅-碳是一种超硬材料和间接带隙半导体。此外，I4̅-碳在线性体模量、剪切各向异性因子、通用各向异性指数和杨氏模量方面表现出较小的弹性各向异性。
