The most widely studied ferroelectric materials are ferroelectric polycrystalline ceramics belonging to the octahedral cubic perovskite structure in the form of ABO3. Barium Titanate (BaTiO3) was the first perovskite to be discovered back in mid 1940s with unusual high dielectric constant; and a decade later, lead Zirconate Titanate (PZT) was reported. In practical applications, PZT and barium strontium Titanate have already dominated many fields of smart technologies.14 Ferroelectricity is not limited to inorganic materials.
Different polymers have shown ferroelectric properties, among them for instance poly(vinylidene fluoride) (PVDF), nylon, cyanopolymers, polythioureas and polyureas.15 Although their ferroelectric parameters (such as Pr) are poorer with respect to inorganic materials, ferroelectric polymers received considerable attention in the last decades especially due to their processing simplicity, good mechanical properties, flexibility and typically low temperature fabrication requirements.16-18
