Microscopic Insights on the Multiferroic Perovskite‐Like [CH3NH3][Co(COOH)3] Compound

Abstract The characterization of the crystal structure, phase transitions, magnetic structure and dielectric properties has been carried out on [CH3NH3][Co(COOH)3] (1) perovskite‐like metal–organic compound through variable‐temperature single‐crystal and powder neutron and X‐ray diffraction and relative permittivity measurements. The paraelectric to antiferroelectric‐like phase transition observed at around 90 K is triggered by a structural phase transition; the structural studies show a change from Pnma space group at RT (1A) to P21/n space group at low temperature (1B). This phase transition involves the occurrence of small distortions in the framework and counterions. Neutron diffraction studies have shown a magnetic order showing spontaneous magnetization below 15 K, due to the occurrence of a non‐collinear antiferromagnetic structure with a weak ferromagnetic component, mainly due to the single‐ion anisotropy of the CoII ions.