ja8b13584_si_004.cif (7.64 kB)
Ferromagnetic van der Waals Crystal VI3
datasetposted on 2019-03-11, 00:00 authored by Shangjie Tian, Jian-Feng Zhang, Chenghe Li, Tianping Ying, Shiyan Li, Xiao Zhang, Kai Liu, Hechang Lei
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 Ts ≈ 79 K, similar to CrX3 (X = Cl, Br, I). Below Ts, a long-range ferromagnetic (FM) transition emerges at Tc ≈ 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.