High-Energy Proton-Irradiation Effects on the Magnetism of the Transition-Metal Dichalcogenide MoS2

Abstract

We have studied the effects of high-energy proton irradiation on the magnetism of the transition-metal dichalcogenide MoS2. The pristine sample showed ferromagnetic and paramagnetic responses with a diamagnetic background, which all decreased initially with increasing irradiation dose. The ferromagnetic component increased subsequently with further irradiation, for which a spin-3/2 species was identified from the analysis of the M(H) curve, in contrast to the spin-1 species identified in the pristine sample. The magnetism in our MoS2 samples may be accounted for by the structural defects that apparently are cured by low-dose proton irradiation and subsequently become significant by further irradiation.