First-principles Studies On Electronic And Magnetic Properties Of Vanadium Disulfide

Vanadium disulfide(VS₂),has the intrinsic ferromagnetic properties with experiment confirmed.The point defect is thermodynamic equilibrium,it is hard to avoid in material growth process.Nowadays,the introduction of the point defects effects on the magnetic properties of VS₂is not clarified.In addition,when VS₂transition from 2D to one dimensional(1D),its magnetic ground state and the change of the nature of the magnetic coupling is also unclear.In this paper,based on the first-principles calculation,studied the magnetic properties of mono-layer VS₂along with the change of S vacancy concentration,and the strain of mono-layer VS₂with point defects.Explored the size of the change on the influence of the nature of the ground state and the magnetic coupling in the VS₂nanosheet.In this paper,first-principles studies on electronic and magnetic properties of VS₂for experimental synthesis and spintronic synthesis provided a new idea.At the same time,it is also provided a theoretical basis to research other magnetic materials.And got the conclusions as following:1.Mono-layer VS₂average atomic magnetic moment along with the increase of S vacancy concentration decreased;S vacancy concentration below 2.00%presents a ferromagnetic semiconductor features,and presents the antiferromagnetic semiconductor features more than 12.50%,between the two presents a ferromagnetic metal or the ferromagnetic semiconductor properties.2.Biaxial compressive strain does not change the ferromagnetic properties on mono-layer VS₂with point defects,while biaxial tensile strain can transfer the ferrimagnetic order into the ferromagnetic order;When strain is from-5%to 5%,its have taken placed in the system of metal-half metal-semiconductor process.3.VS₂nanosheet is long-range ferromagnetic sequence along the periodic direction,the ferromagnetic coupling strength weakened gradually with the decreasing of the size.When the size reduced to 2 nm,the ferromagnetic coupling strength is enhanced.4.In addition to the atomic magnetic moment edge V,V atomic magnetic moment is greater than mono-layer VS₂V atomic magnetic moment.And its ferromagnetic coupling strength is mainly determined by the through-bond mechanism.