College of Physics Science and Technology, Yangzhou University, Yangzhou, 225002, China.
Nanoscale. 2017 Aug 10;9(31):11231-11238. doi: 10.1039/c7nr03581k.
The energetics and electronic and magnetic properties of G/MS hybrid structures embedded with 3d transition metal atoms, TM@(G/MS) (G = graphene; M = W, Mo; TM = Sc-Ni), have been systematically studied using first-principles calculations. TM atoms were found to be covalently bound to two-sided graphene and MS layers with sizable binding energies of 4.35-7.13 eV. Interestingly, a variety of electronic and magnetic properties were identified for these TM@(G/MS) systems. Except for TM = Ni, all other systems were ferromagnetic, due to exchange splitting of the TM 3d orbitals. In particular, four TM@(G/MoS) systems (TM = V, Mn, Fe, Co) and three TM@(G/WS) systems (TM = Mn, Fe, Co) were half-metals or quasi half-metals, while Ni@(G/MoS) and Ni@(G/WS) were semiconductors with bandgaps of 33 and 37 meV, respectively. Further quasi-particle scattering theory analysis demonstrated that the origin of semiconducting or half-metallic properties could be well understood from the variation in on-site energy by the transition metal dichalcogenide substrate or the different on-site scattering potential induced by TM atoms. Our findings propose an effective route for manipulating the electronic and magnetic properties of graphene@MS heterostructures, allowing their potential application in modern spintronic and electronic devices.
使用第一性原理计算系统地研究了嵌入 3d 过渡金属原子（TM@(G/MS)，G=石墨烯；M=W，Mo；TM=Sc-Ni）的 G/MS 杂化结构的能量学和电子及磁性性质。TM 原子与两面石墨烯和 MS 层以 4.35-7.13 eV 的大结合能发生共价键合。有趣的是，这些 TM@(G/MS) 体系具有多种电子和磁性性质。除了 TM=Ni 之外，所有其他体系都是铁磁性的，这是由于 TM 3d 轨道的交换分裂所致。特别地，四个 TM@(G/MoS)体系（TM=V，Mn，Fe，Co）和三个 TM@(G/WS)体系（TM=Mn，Fe，Co）是半金属或准半金属，而 Ni@(G/MoS)和 Ni@(G/WS)分别是半导体，带隙分别为 33 和 37 meV。进一步的准粒子散射理论分析表明，通过过渡金属二硫属化物衬底或 TM 原子引起的不同局域散射势来改变局域能量，可以很好地理解半导体或半金属性质的起源。我们的研究结果为操控石墨烯@MS 异质结构的电子和磁性性质提供了有效途径，使其在现代自旋电子学和电子器件中具有潜在的应用前景。
