Synergetic Effect of Substitutional Dopants and Sulfur Vacancy in Modulating the Ferromagnetism of MoS2 Nanosheets.

The activation and modulation of the magnetism of MoS2 nanosheets are critical to the development of their application in next-generation spintronics. Here, we report a synergetic strategy to induce and modulate the ferromagnetism of the originally nonmagnetic MoS2 nanosheets. A two-step experimental method was used to simultaneously introduce substitutional V dopants and sulfur vacancy (Vs) in the MoS2 nanosheet host, showing an air-stable and adjustable ferromagnetic response at room temperature. The ferromagnetism could be modulated by varying the content of Vs through Ar plasma irradiation of different periods, with a maximum saturation magnetization of 0.011 emu g-1 reached at the irradiation time of 6 s (s). Experimental characterizations and first-principles calculations suggest that the adjustable magnetization is attributed to the synergetic effect of the substitutional V dopants and Vs in modulating the band structure of MoS2 nanosheets, resulting from the strong hybridization between the V 3d state and the Vs-induced impurity bands. This work suggests that the synergetic effect of substitutional V atoms and Vs is a promising route for tuning the magnetic interactions in two-dimensional nanostructures.