Effect of strain on the magnetic states of transition-metal atoms doped monolayer WS2

The effects of transition-metal atoms doping and elastic strain on the magnetic properties of monolayer WS2 are investigated by the first-principles calculation. Firstly, we investigate the magnetic properties of a series of 3d transition-metal atoms (from Sc to Zn) doped monolayer WS2. Our calculations show that doping of transition-metal atoms from Sc to Cr results in nonmagnetic states, while Mn, Fe, Co, Ni, Cu and Zn doping can induce magnetism in WS2 monolayer. The localized nonbonding 3d electrons of TM atoms lead to the formation of magnetic moments. Meanwhile, our calculations indicate that the elastic strain can be used to manipulate the spin polarization of TM-3d orbital. Specifically, the magnetic moment of Fe and Co-doped monolayer WS2 increase with the increase of tensile strain, while the magnetic moment of Mn, Ni, Cu and Zn-doped WS2 monolayer initially increase and then decrease with the increase of tensile strain. On the other hand, the magnetic moment of Fe, Co, Mn, Ni, Cu and Zn-doped WS2 monolayers decrease with the increase of compressive strain. While the magnetic moment of Sc, Ti, V and Cr-doped WS2 monolayers remain 0 mu(B) independent of tensile strain and compressive strain. (C) 2016 Elsevier B.V. All rights reserved.