Magnetic and dielectric properties of [N(C2H5)4]2CoClBr3 solid solution: A new potential multiferroic

Thermodynamically induced structural transformation to a polar phase in the tetraethylammonium tetrahalogenocobaltate solid solution of [N(C2H5)4]2CoClBr3 (TEACCB-3) is found to be accompanied with a large dielectric permittivity peak near 258 K. It was also found that the sample undergoes a ferrimagnetic ordering on further cooling below 8 K. Our results demonstrate that crystalline ferroics with an alkylammonium cation can develop strong magnetic interactions reaching 2.3 μB fu−1 at 14 T that can potentially coexist with electric polarization at the same temperature region.