Co对单层MoS_2电子结构与磁性的影响

Electronic and magnetic properties of monolayer MoS_2 with cobalt doping

为了研究Co对单层MoS_2电子结构和磁性的影响,本文基于第一性原理,采用数值基组的方法计算了Co吸附式掺杂、Co替代式掺杂单层MoS_2的能带结构、态密度以及分析了其结构的稳定性.结果发现:Co替换式掺杂体系的形成能较低,实验上容易实现;Co在Mo位吸附的稳定性强于在S位吸附;Mo位吸附体系的总磁矩为0.999μB,其磁矩的主要来源于Co原子的吸附所贡献的0.984μB,Co原子的掺杂体系总磁矩为1.029μB,其磁矩的主要由Co原子替代掉一个Mo原子所贡献的磁矩为0.9444μB,相比于吸附体系,Co原子对磁矩的贡献率有所降低;无论是Co吸附在单层MoS_2表面还是Co直接替代掉Mo原子的掺杂体系,Co原子3d轨道的引入是引起单层MoS_2体系磁性的主要原因.

In order to study, the electronic structure and magnetic properties of monolayer MoS2 were affected by doping Co atoms, this paper based on the first principles, calculated the band structures and density of states of Co -doped monolayer MoS2 and analyzed the stability of the structure by adopting the numeric basis sets method. It was identified that the formation energy of Co substitution doping system is lower and easy to implement in the experiment. The adsorption of cobalt at Mo position is more stable than at S. The total magnetic moment of Co adsorption at Mo site system is 0. 999μB, and mainly comes from 0. 984μB which contribute by adsorption of Co atom. The total magnetic moment of Co doped monolayer MoS2 is 0. 999μB. The magnetic moment of Mo atom, which is replaced by a Co atom, is 0. 9444μB. Compared with the adsorption system, the contribution rate of Co atoms to the magnetic moment decreased. Whether Co adsorption on the surface of monolayer MoS2 or Co doped Mo atoms replace directly, the Co atom 3d orbitals is the main reason for the magnetic properties of monolayer MoS2 system.