Kah C B, Yu M, Tandy P, Jayanthi C S, Wu S Y
Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky, 40292, USA.
Nanotechnology. 2015 Oct 9;26(40):405701. doi: 10.1088/0957-4484/26/40/405701. Epub 2015 Sep 16.
One-dimensional icosahedral boron chains and two-dimensional icosahedral boron sheets (icosahedral α, δ6, and δ4 sheets) that contain icosahedra B12 as their building units have been predicted in a computer simulation study using a state-of-the-art semi-empirical Hamiltonian. These novel low-dimensional icosahedral structures exhibit interesting bonding and electronic properties. Specifically, the three-center, two-electron bonding between icosahedra B12 of the boron bulk (rhombohedral boron) transforms into a two-center bonding in these new allotropes of boron sheets. In contrast to the previously reported stable buckled α and triangular boron monolayer sheets, these new allotropes of boron sheets form a planar network. Calculations of electronic density of states (DOS) reveal a semiconducting nature for both the icosahedral chain and the icosahedral δ6 and δ4 sheets, as well as a nearly gapless (or metallic-like) feature in the DOS for the icosahedral α sheet. The results for the energy barrier per atom between the icosahedral δ6 and α sheets (0.17 eV), the icosahedral δ6 and δ4 sheets (0.38 eV), and the icosahedral α and δ4 sheets (0.27 eV), as indicated in the respective parentheses, suggest that these new allotropes of boron sheets are relatively stable.
在一项使用最先进的半经验哈密顿量的计算机模拟研究中，预测了以二十面体B12为构建单元的一维二十面体硼链和二维二十面体硼片（二十面体α、δ6和δ4片）。这些新颖的低维二十面体结构展现出有趣的键合和电子性质。具体而言，硼块体（菱面体硼）中二十面体B12之间的三中心两电子键合在这些新的硼片同素异形体中转变为两中心键合。与先前报道的稳定的弯曲α和三角形硼单层片不同，这些新的硼片同素异形体形成平面网络。电子态密度（DOS）计算表明，二十面体链以及二十面体δ6和δ4片均具有半导体性质，而二十面体α片的DOS具有近乎无隙（或类金属）特征。如各自括号中所示，二十面体δ6和α片之间（0.17 eV）、二十面体δ6和δ4片之间（0.38 eV）以及二十面体α和δ4片之间（0.27 eV）的每原子能量势垒结果表明，这些新的硼片同素异形体相对稳定。
