Facile Synthesis of Single Crystal, Room-Temperature Ferromagnetic Monolayer Vanadium Disulfide by Chemical Vapor Deposition
Sheng-Kuei Chiu1*, Cheng-Chi Peng1, Mario Hofmann2, Ya-Ping Hsieh3, Hao-Ting Chin3, Ding-Rui Chen3
1Department of Materials Science and Engineering, Feng Chia University, Taichung, Taiwan
2Institute of Physics, National Taiwan University, Taipei City, Taiwan
3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei City, Taiwan
* Presenter:Sheng-Kuei Chiu, email:skuechiu@fcu.edu.tw
Single-crystal monolayer vanadium disulfide (VS2) is synthesized by atmospheric pressure chemical vapor deposition (APCVD). The morphology and thickness of VS2 synthesized with APCVD is a single layer trigonal flake with a thickness of 0.74 nm and a size of 5-10 m, confirmed by atomic force microscopy (AFM). Raman spectra are collected and consistent with the trigonal phase's vibrational modes, which exits A1g and E2g Raman vibrational modes, corresponding to 405.51cm-1 and 383.87cm-1, respectively. Electron dispersive spectroscopy (EDS) is utilized for elemental analysis of the VS2 sample, and it is found that the ratio of V: S in VS2 is about 1: 2.2, which is close to 1: 2. The hexanol single-crystal structure is analyzed via transmission electron microscopy (TEM). Room-temperature ferromagnetic response via magnetic force microscopy (MFM) is detected in our monolayer trigonal VS2 flake, and both magneto-optic Kerr effect (MOKE) measurements and vibrating-sample magnetometer (VSM) analysis present ferrimagnetic property at room temperature. This discovery of magnetic property in our single layer VS2 may impact spintronics and other ferromagnetic properties related to electronic device applications.

Keywords: 2D nanomaterials, CVD, Transition Metal Dichalcogenides, Ferromagnetic, spintronics