Halogenoantimonates(III) and Halogenobismuthates(III)—A Rich Family of Ferroelectric Crystals

In this paper a variety of architectures of self-assembled halo-coordinated MX6 octahedra in ferroelectric halogenoantimonates(III) and halogenobismuthates(III) is illustrated. The dielectric properties of a new ferroelectric [4-NH2C5H4NH][SbCl4] are presented. The para-ferroelectric phase transitions mechanism (C2/c → Cc) at Tc = 270.5 K is discussed. The phase situation in the [4-NH2C5H4NH][MX4] (where M = Sb, Bi and X = Cl, Br) family is compared.