Ultrahigh-temperature ferromagnetism in MoS 2 Moiré superlattice/graphene hybrid heterostructures

Realizing high-temperature ferromagnetism in two-dimensional (2D) semiconductor nanosheets is significant for their applications in next-generation magnetic and electronic nanodevices. Herein, this goal could be achieved on a MoS2 Moire superlattice grown on the reduced graphene oxide (RGO) substrate by a hydrothermal approach. The as-synthesized bilayer MoS2 superlattice structure with rotating angle (ϕ = 13° ± 1°) of two hexagonal MoS2 lattices, possesses outstanding ferromagnetic property and an ultra-high Curie temperature of 990 K. The X-ray absorption near-edge structure and ultraviolet photoelectron spectroscopies combined with density functional theory calculation indicate that the covalent interactions between MoS2 Moire superlattice and RGO substrate lead to the formation of interfacial Mo-S-C bonds and complete spin polarization of Mo 4d electrons near the Fermi level. This design could be generalized and may open up a possibility for tailoring the magnetism of other 2D materials.