Magnetic properties of van der Waals layered single crystals DyOBr and SmOCl

Two-dimensional van der Waals single crystals DyOBr and SmOCl have been grown by a flux method, and their anisotropic magnetic properties are reported. DyOBr orders antiferromagnetically at TN = 9.5 K with magnetic moments lying along a axis, similar as DyOCl. Its magnetic susceptibility shows an anomaly at T* = 30 K, possibly due to the crystal field effect. Furthermore, a 1/3 magnetization plateau is clearly observed under H II a and H II [110], which might be a field-induced spin-flop phase or some exotic quantum magnetic state. On the other hand, isostructural SmOCl undergoes an antiferromagnetic transition at TN = 7.1 K and exhibits a contrasting Ising-like perpendicular c-axis magnetic anisotropy, which could be well explained by our crystal field calculations. Both DyOBr and SmOCl are insulators with a band gap of -5 eV, and our results suggest they are promising in building van der Waals heterostructures and applications in multifunctional devices.