Fujian Provincial Key Laboratory of Functional Marine Sensing Materials, Center for Advanced Marine Materials and Smart Sensors, Minjiang University, Fuzhou 350108, P. R. China.
Phys Chem Chem Phys. 2019 Nov 21;21(43):24212-24217. doi: 10.1039/c9cp04913d. Epub 2019 Oct 29.
In this paper, we designed a two-dimensional honeycomb monolayer ZrBC, which is predicted to be a stable nanosheet and exhibits favorable mechanical and thermal properties. The Young's modulus of ZrBC is 122.3 N m, which is about one third of that of graphene. The ab initio molecular dynamics (AIMD) results show that ZrBC can sustain up to 500 K. In addition, ZrBC is semi-metallic and it exhibits twelve Dirac cones in the first Brillouin zone; the six pairs of Dirac cones form compensated electron-hole pockets, and the maximum Fermi velocity is about 6.3 × 10 m s, which is about 60% of that of graphene. Compared with other transition metal borides which possess Dirac states, the twelve Dirac cones are all robust under different types of external strains, and the Dirac states could be shifted along the opposite direction crossing the Fermi energy barrier by external strains and the gap of the two Dirac cones could be opened around the Fermi energy level with the effect of spin-orbit coupling.
在本文中，我们设计了一种二维蜂窝状单层 ZrBC，预测其为稳定的纳米片，同时表现出良好的力学和热学性能。ZrBC 的杨氏模量为 122.3 N m，约为石墨烯的三分之一。基于第一性原理分子动力学 (AIMD) 的结果表明，ZrBC 可以承受高达 500 K 的温度。此外，ZrBC 是半金属的，在第一布里渊区中存在十二个狄拉克锥；六对狄拉克锥形成补偿电子-空穴口袋，最大费米速度约为 6.3×10 m s，约为石墨烯的 60%。与具有狄拉克态的其他过渡金属硼化物相比，在不同类型的外部应变下，这十二个狄拉克锥都是稳定的，并且通过外部应变可以沿着相反的方向将狄拉克态转移，越过费米能级势垒，同时在自旋轨道耦合的作用下，两个狄拉克锥之间的能隙可以在费米能级附近打开。
