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

Abstract

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 ∼ 0.7 nm. Further, the room temperature magnetic force microscopy (MFM) study gives a phase shift of 0.68° to 0.06° 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 VS_2, indicating robust experimental evidence for the magnetic behavior of monolayer H-phase VS_2. Our study introduces a pathway to explore the opportunity for highly efficient future spintronic devices using 2D magnetic materials at RT.