Magnetic response of monolayer H-phase VS2 nanosheets at room temperature: Implications for spintronics device

Background: Transition metal dichalcogenides (TMDs), explicitly monolayer vanadium disulfide (VS2) in its H-phase, have gained remarkable attention due to their semiconducting nature, intrinsic magnetic properties at room temperature (RT), and potential use in future spintronic devices. Method: In this study, we report an optimized, simple, and scalable synthesis of monolayer H-phase VS2 crystal using an atmospheric pressure chemical vapor deposition (APCVD) technique. Significant findings: The Raman spectra and High-resolution transmission electron microscopy (HRTEM) image of the as-synthesized VS2 crystal reveal that the as-synthesized sample has an H-phase, and atomic force microscopy (AFM) confirms the presence of a monolayer with a step height of similar to 0.7 nm. Further, the room temperature magnetic force microscopy (MFM) study gives a phase shift of 0.68 degrees to 0.06 degrees for the sample-tip variation from 20 nm to 140 nm in steps of 20 nm, suggesting an intrinsic long-range magnetic ordering in the as-synthesized VS2 crystal. The decrease in the MFM phase shift exhibits exponential dependence on the sample to AFM tip distance. Finally, our MFM phase shift measurement findings suggest a RT magnetic response in monolayer H-phase VS2 crystal. These results are much higher than the other previously reported MFM responses of metallic T-phase VS2, indicating robust experimental evidence for the magnetic behavior of monolayer H-phase VS2. Our study introduces a pathway to explore the opportunity for highly efficient future spintronic devices using 2D magnetic materials at RT.