Effect of morphology and stacking on atomic interaction and magnetic characteristics in two-dimensional H-phase VS2 few layers

Recently, the research of two-dimensional layered transition metal dichalcogenides has made great progress due to their high potential in advanced electronic devices. In this work, H-phase VS2 atomic layers with different morphologies and stacking orders were successfully synthesized on sapphire via chemical vapor deposition. The H-phase VS2 shows semiconductor characteristic with its valence band maximum located similar to 0.25 eV below the Fermi level. Interlayer many-body interactions are strongly stacking-dependent, leading to distinguished intensity ratio between the breathing and shear modes, 2.99 +/- 0.94 for AA, and 1.72 +/- 0.26 for AB stacking. The intralayer S-Vinteraction (force constant: 2.80-3.54 x 10(21) N/m(3)) is two orders of magnitude larger than the interlayer S-S interaction (force constant: 1.98-6.70 x 10(19) N/m(3)). The shear modulus is further derived to be similar to 12.8 GPa, similar to 30% smaller than that of MoS2. The prepared VS2 film exhibits obvious magnetic behavior at room temperature with the attenuation distance of similar to 16-25 nm in out-of-plane direction. The morphology dependent magnetism and stability investigations indicate that the measured magnetic behaviors of the sample have a certain degree of extrinsic contributions, which may settle down some experimental controversies about the magnetic behaviors in this specific system.

Automated summary

This research successfully synthesized H-phase VS2 atomic layers with different morphologies and stacking orders, and discovered their semiconductor characteristic. The interlayer interactions are stacking-dependent, while the intralayer interaction is two orders of magnitude larger than the interlayer interaction. The shear modulus and magnetic behavior of the VS2 film are also investigated.