Gallium nitride and zinc oxide can also be regarded as a ceramic due to their relatively wide band gaps.
Inorganic ceramic PMs offer advantages over single crystals, including ease of fabrication into a variety of shapes and sizes not constrained crystallographic directions.
Moreover, piezoelectric polymeric sensors and actuators, due to their processing flexibility, can be readily manufactured into large areas, and cut into a variety of shapes.
Furthermore, they show low Curie temperature, leading to constraints in terms of applications in harsh environmental conditions.
Also, several ferroelectrics with perovskite-structure (BaTiO3 [BT], (Bi1/2Na1/2) TiO3 [BNT], (Bi1/2K1/2) TiO3 [BKT], KNbO3 [KN], (K, Na) NbO3 [KNN]) have been investigated for their piezoelectric properties.