Ferromagnetic van der Waals Crystal VI3

Shangjie Tian; Jian-Feng Zhang; Chenghe Li; Tianping Ying; Shiyan Li; Xiao Zhang; Kai Liu; Hechang Lei

doi:10.1021/jacs.8b13584

Ferromagnetic van der Waals Crystal VI₃

J Am Chem Soc. 2019 Apr 3;141(13):5326-5333. doi: 10.1021/jacs.8b13584. Epub 2019 Mar 25.

Authors

Shangjie Tian¹, Jian-Feng Zhang¹, Chenghe Li¹, Tianping Ying², Shiyan Li^{2

3}, Xiao Zhang⁴, Kai Liu¹, Hechang Lei¹

Affiliations

¹ Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , P. R. China.
² State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials , Fudan University , Shanghai 200438 , P. R. China.
³ Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , P. R. China.
⁴ State Key Laboratory of Information Photonics and Optical Communications & School of Science , Beijing University of Posts and Telecommunications , Beijing 100876 , P. R. China.

PMID: 30856325
DOI: 10.1021/jacs.8b13584

Abstract

We report structural properties, physical properties, and the electronic structure of van der Waals (vdW) crystal VI₃. Detailed analysis reveals that VI₃ exhibits a structural transition from monoclinic C2/ m to rhombohedral R3̅ at T_s ≈ 79 K, similar to CrX₃ (X = Cl, Br, I). Below T_s, a long-range ferromagnetic (FM) transition emerges at T_c ≈ 50 K. The local moment of V in VI₃ is close to the high-spin state V³⁺ ion ( S = 1). Theoretical calculations suggest that VI₃ may be a Mott insulator with a band gap of about 0.90 eV. In addition, VI₃ has a relatively small interlayer binding energy and can be exfoliated easily down to a few layers experimentally. Therefore, VI₃ is a candidate for two-dimensional FM semiconductors. It also provides a novel platform to explore 2D magnetism and vdW heterostructures in S = 1 system.