Ferroelectricity in a lead free organic–inorganic 0D hybrid: formamidinium bromoantimonate( iii )

A multiphase, low-temperature ferroelectric of haloantimonate( iii ) with a unique R 5 M 2 X 11 composition and P s of about 3 μC cm −2 resulting from the ‘order–disorder’ and ‘displacive’ molecular mechanism is successfully synthesized and characterized.