Dielectric, Ferroelectric, and Strain Study of BNT-BT-BKT Ceramics for Actuator Applications

The 0.88Bi0.5Na0.5TiO3-0.04BaTiO3-0.08Bi0.5K0.5TiO3 (BNT-BT-BKT) ceramics were synthesized by a conventional solid-state reaction, and their structural, dielectric, polarization versus electric field (P–E), and induced strain versus electric field (S–E) properties were studied in detail. The structural study confirmed the morphotropic phase boundary nature of the ceramics. The depolarization temperature (Td) and Curie temperature (Tc) were found to be ∼ 70°C and 299°C, respectively, which correspond to ferroelectric to antiferroelectric and antiferroelectric to paraelectric phase transitions, respectively. Remnant polarization (Pr) of ∼ 22 μC/cm2, a coercive field (Ec)  of ∼ 22 kV/cm, and an electric field-induced maximum strain% of ∼ 0.63 were observed in the ceramics. as well as good ferroelectric properties, the high induced strain% points to the usefulness of this system for actuator applications.