Interface-enhanced Magnetism in Two-dimensional V-doped MoS₂/Graphene Heterostructures

While two-dimensional transitional metal dichalcogenides (2D-TMDs) semiconductors often possess no magnetic orderings in their pristine forms, magnetic doping or coupling them to magnetic substrates can induce room-temperature ferromagnetism in these monolayers. Stacking 2D-TMDs with other 2D van der Waals materials, such as graphene, may offer a fertile ground for exploring interface-mediated magnetic phenomena in van der Waals heterostructures. This study demonstrates the interface-enhanced magnetism in monolayers of pristine (MoS₂) and V-doped MoS₂ stacked with graphene. We grow MoS₂ and V-MoS₂ monolayers by the chemical vapor deposition method and then transfer them onto graphene layers on Si/SiO₂ substrates. Magnetometry measurements reveal a significant enhancement in saturation magnetization (M_S) of the MoS₂/graphene and V-MoS₂/graphene heterostructures compared to the MoS₂ and V-MoS₂ monolayers on Si/SiO₂ substrates. This difference in M_S became more significant after annealing the heterostructure at 300^oC to enhance stacking adherence and strengthen the bonding between MoS₂ and graphene. It implies a vital role of interfacial couplings in facilitating charge transfer across their semiconductor/metal interface and manipulating the magnetic properties of the heterostructures. These findings pave a new pathway for developing novel van der Waals magnetic heterostructures for the next generation of spintronic, valleytronics, and opto-spincaloritronic devices.