Magnetism in MoS2 induced by proton irradiation

Molybdenum disulphide, a diamagnetic layered dichalcogenide solid, is found to show magnetic ordering at room temperature when exposed to a 2 MeV proton beam. The temperature dependence of magnetization displays ferrimagnetic behavior with a Curie temperature of 895 K. A disorder mode corresponding to a zone-edge phonon and a Mo valence higher than +4 has been detected in the irradiated samples using Raman and x-ray photoelectron spectroscopy, respectively. The possible origins of long-range magnetic ordering in irradiated MoS2 samples are discussed.