Strain Control To Magnetic Properties Of 3d Transition Metal Doped Single-layer MoS₂:first Principles Study

Two-dimensional(2D) monolayer materials have triggered tremendous interests due to their excellent properties and promising application in ultimately small quantum devices. Similarly, the 2D molybdenum disulfide(MoS2) sheet is also promising candidates for nanoscale device with novel physical properties. In particular, monolayer MoS2 sheet is predicted as a direct gap semiconductor with a1.9eV gap, which makes it powerful in nanoelectronic applications like preparation of effective room temperature field-effect transistors(FET). Moreover, the manipulation of electronic structure and magnetism is very crucial to realize its application in nanoelectronics. On the other hand, introduced transition metal(TM) in 2D system is an effective approach to modulate magnetic and electronic properties. Therefore,strain engineering could be a promising way to tune the magnetic property for TM doped 2D system. Magnetic anisotropy is the most significant quantity for application of magnetic storage device. Many results have showed the reduced symmetry and low dimensions may result in appreciable magnetic anisotropy energy(MAE). In the present study, we perform first-principles calculations to explore the influence of the strain control on the electronic structure, magnetic states and magnetic anisotropy of Fe, Mn, Cr doped on the S vacancy of MoS2 sheets. The main conclusions and results as follows:We investigate the strain control of electronic structure and magnetic states for single Fe, Mn and Cr atom doped single-layer MoS2 sheet by density functional theory(DFT). Using the density of states, bandgap, difference of the charge density,we explore the mechanism of the effect of strain on the electronic structure and magnetic states. We found that a small amount of biaxial tensile strain(0%-6%) can effective enhance the magnetic moment of the Fe-MoS2 system, whereas the magnetic moments of Mn-MoS2, Cr-MoS2 and Co-MoS2 is unchanged. And when the strain reaches a critical strain(3.5%), the Fe-MoS2 system undergo transition of magnetic states from 2.04μB to 4μB. In the same time, the coupling between Fe and the three nearest Mo atom have changed. The strain can efficiently modulates the electronic structures of Fe-MoS2 system and introduces excellent electronic feature, such as spin-gapless semiconductor and bipolar magnetic semiconductor.Moreover, due to the reduced dimensions for Fe-MoS2, magnetic anisotropy can be enhanced and show unique properties. Based on the above works, the SOC was taken into account to analysis the effect of strain on magnetic anisotropy energy. we found that the magnetic anisotropy energy is sensitive to strain and Fe-MoS2 system show spin reorientation from out-of-plane to in-plane magnetization at 3% strain. Our results provide a new approach of locally controlling and switching magnetism for MoS2-based atomic structure device in spintroncis.