Wei Lin, Zhang Xiaoming, Zhao Mingwen
School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China.
Phys Chem Chem Phys. 2016 Mar 21;18(11):8059-64. doi: 10.1039/c6cp00368k.
Dirac cones in the band structure make a great contribution to the unique electronic properties of graphene. But the spin-degeneracy of Dirac cones limits the application of graphene in spintronics. Here, using first-principles calculations, we propose a two-dimensional (2D) metal-organic framework (MOF), Ni2C24S6H12, with spin-polarized Dirac cones at the six corners of the Brillouin zone (BZ). Ferromagnetism is quite stable with a high Curie temperature (630 K) as revealed by Monte Carlo simulation within the Ising model. Taking spin-orbit coupling into account, band gaps are opened up at the Dirac point (5.9 meV) and Γ point (10.4 meV) in the BZ, making Ni2C24S6H12 a Chern topological insulator which is implemented for achieving the quantum anomalous Hall effect. These interesting properties enable Ni2C24S6H12 to be a promising candidate material for spintronics device applications.
能带结构中的狄拉克锥对石墨烯独特的电子性质贡献巨大。但狄拉克锥的自旋简并性限制了石墨烯在自旋电子学中的应用。在此，我们通过第一性原理计算，提出了一种二维金属有机框架（MOF），即Ni2C24S6H12，其在布里渊区（BZ）的六个角上具有自旋极化的狄拉克锥。如伊辛模型内的蒙特卡罗模拟所示，铁磁性相当稳定，居里温度高达630 K。考虑到自旋轨道耦合，BZ中的狄拉克点（5.9 meV）和Γ点（10.4 meV）处会打开带隙，使Ni2C24S6H12成为一种用于实现量子反常霍尔效应的陈拓扑绝缘体。这些有趣的性质使Ni2C24S6H12成为自旋电子器件应用中一种很有前景的候选材料。
