Ferromagnetic Coupling in Quasi-One-Dimensional Hybrid Iron Chloride Hexagonal Perovskites

We synthesize four novel quasi-one-dimensional organic-inorganic hybrid iron chloride compounds (CH₃NH₃FeCl₃, CH(NH₂)₂FeCl₃, C(NH₂)₃FeCl₃, and C₃H₅N₂FeCl₃) and characterize their structural and magnetic properties. These materials crystallize in a hexagonal perovskite-type structure, constituting a triangular array of face-sharing iron chloride octahedra chains running along the c-axis, isolated from one another by the organic cation. Through magnetization and heat capacity measurements, we find that the intrachain coupling is weakly ferromagnetic for each variant. Importantly, this work underscores the utility of solid-state chemistry approaches in synthesizing new organic-inorganic hybrid materials.