Two-dimensional meta-magnetism in van der Waals layered material Cu_2xFe_1−xPS₃

Complex magnetic ordering such as meta-magnetism and skyrmions is attractive for its potential applications in spintronics and fundamental understanding of magnetism. However, complex magnetic ordering is rarely observed in intrinsic van der Waals layered materials, limiting the exploration of two-dimensional (2D) magnetism. Here, we successfully synthesized a novel compound, Cu_2xFe_1−xPS₃, which represents the first meta-magnetic van der Waals material with field-induced ferromagnetism. In this compound, monovalent Cu partially replaces the Fe positions in the FePS₃ lattice in the form of dimers. The substitution of Cu breaks the 2D Ising antiferromagnetic structure, resulting in the complex coexistence of weak ferromagnetism and antiferromagnetism. Importantly, field-induced ferromagnetism is observed when the external magnetic field is perpendicular to the ab plane of the material. The nature of the meta-magnetic transition is attributed to the uncompensated antiferromagnetism with noncollinear magnetic structure under external magnetic field. Our work paves the way to realize 2D complex magnetic ordering.