Enhanced room temperature ferromagnetism in MoS2 by N plasma treatment

The introduction of ferromagnetism in MoS2 is important for its applications in semiconductor spintronics. MoS2 powders were synthesized by hydrothermal method, followed by the N plasma treatment at room temperature. Weak ferromagnetism with saturated ferromagnetic magnetization of 0.64 memu/g has been observed in the as-synthesized MoS2 at room temperature, which is significant enhanced to 3.67 memu/g after the N plasma treatment for the proper duration. X-ray photoelectron spectroscopy demonstrates the adsorption of N, and higher valence state of Mo than +4 due to the bonding with N after the N plasma treatment. First principle calculation has been performed to disclose the possible origin of ferromagnetism. One chemical adsorbed N ion on S ion may form conjugated π bonds with adjacent two Mo ions to have a total magnetic moment of 0.75 μB, contributing to the enhanced ferromagnetism.The introduction of ferromagnetism in MoS2 is important for its applications in semiconductor spintronics. MoS2 powders were synthesized by hydrothermal method, followed by the N plasma treatment at room temperature. Weak ferromagnetism with saturated ferromagnetic magnetization of 0.64 memu/g has been observed in the as-synthesized MoS2 at room temperature, which is significant enhanced to 3.67 memu/g after the N plasma treatment for the proper duration. X-ray photoelectron spectroscopy demonstrates the adsorption of N, and higher valence state of Mo than +4 due to the bonding with N after the N plasma treatment. First principle calculation has been performed to disclose the possible origin of ferromagnetism. One chemical adsorbed N ion on S ion may form conjugated π bonds with adjacent two Mo ions to have a total magnetic moment of 0.75 μB, contributing to the enhanced ferromagnetism.