Tunable Magnetic Transition Temperatures in Organic–Inorganic Hybrid Cobalt Chloride Hexagonal Perovskites

Magnetically active atomic distances may impact the magnetic ordering in a given system both directly and indirectly. We synthesize three novel quasi-one-dimensional organic–inorganic hybrid cobalt chloride chain compounds (CH 3 NH 3 CoCl 3, CH(NH 2 ) 2 CoCl 3, and C(NH 2 ) 3 CoCl 3 ) and characterize their magnetic and thermodynamic properties. These materials crystallize in a hexagonal perovskite-type structure consisting of chains of face-sharing Co–Cl octahedra separated by the respective organic cation. Temperature- and field-dependent magnetic susceptibility analyses reveal that each compound possesses antiferromagnetic intrachain coupling and that the strength of the correlations is comparable across the three materials. Moreover, the interchain Co–Co distance, which depends on the size of the organic cation, is directly related to the temperature at which long-range magnetic ordering occurs.