Spontaneous magnetization induced by organic ion intercalation in the layered antiferromagnet MnPSe3

Exploring novel two-dimensional (2D) magnetic insulators and achieving tunable magnetic properties are fundamental for their potential applications in information processing and storage. In this work, we report a modulation from antiferromagnetic (AFM) order to a state with spontaneous magnetization through the intercalation of tetrabutylammonium (TBA+) ions in the van der Waals layered antiferromagnet MnPSe3. By employing two distinct electrochemical methods, cyclic voltammetry (CV) and chronopotentiometry, we achieve different transition temperatures, spontaneous magnetizations, and in-plane anisotropies. A spontaneous magnetization of ∼0.38 μB/f.u. (∼6.5 emu/g) is observed in the CV-intercalated samples, which is a record value among the organic-ion-intercalated MPX3 (M = Mn, Fe, Ni, and X = S, Se) compounds. We attribute the spontaneous magnetization behavior to possible canted antiferromagnetism, which may be induced by the modified intralayer exchanges resulting from the TBA+ intercalation. Our results provide a feasible approach for inducing and tuning spontaneous magnetization in 2D AFM insulators.