Identifying the effects of oxygen on the magnetism of WS 2 nanosheets.

In this paper, the microstructure and magnetic properties of the exfoliated and sulfurized WS 2 nanosheets were researched to identify the effects of oxygen on magnetism. The exfoliated WS 2 nanosheets were prepared by a liquid exfoliation method, and then the sulfurized WS 2 nanosheets were obtained after sulfurization of the exfoliated WS 2 nanosheets. The exfoliated WS 2 nanosheets show paramagnetism, and contain 1T and 2H phases, sulfur vacancies and some oxygen. The sulfurized WS 2 nanosheets with an intrinsic structure exhibit an ordered magnetic signature. A combination of detailed experimental research and first-principles calculation demonstrates that oxygen in the structure of WS 2 nanosheets would not induce magnetic moments, which can even suppress the spin-polarized edge states. These results identified the effects of oxygen on the magnetism of WS 2 nanosheets and would promote its application in spintronics.