State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, People's Republic of China.
J Phys Condens Matter. 2012 Oct 10;24(40):405803. doi: 10.1088/0953-8984/24/40/405803. Epub 2012 Sep 18.
A theoretical prediction on the structural stabilities, mechanical properties, and electronic properties of the C-centered orthorhombic (Cco) Si(8) and Ge(8) is presented, inspired by a recently proposed carbon allotrope structure, Cco-C(8). Energetically comparable with previously known metastable phases, Cco-Si(8) and Cco-Ge(8) may be obtained by decompressing the high-pressure β-Sn phases, or by compressing the corresponding nanotubes. The calculated bulk moduli of Cco-Si(8) and Cco-Ge(8) are close to those of the diamond phases. Further study of the electronic properties reveals that the band gaps of Cco-Si(8) and Cco-Ge(8) are tunable with variations in lattice parameters.
本文提出了一种关于 C 中心正交（Cco）Si（8）和 Ge（8）结构稳定性、力学性能和电子性能的理论预测，这一预测受到了最近提出的碳同素异形体结构 Cco-C（8）的启发。Cco-Si（8）和 Cco-Ge（8）与先前已知的亚稳相在能量上是可比的，它们可以通过压缩高压β-Sn 相或压缩相应的纳米管来获得。计算得到的 Cco-Si（8）和 Cco-Ge（8）的体弹性模量接近金刚石相。进一步研究电子性能表明，Cco-Si（8）和 Cco-Ge（8）的能带隙可以通过晶格参数的变化来调节。
