Large electrostrictive effect and dielectric properties of (K0.5Na0.5)NbO3-BaZrO3 ceramics

Electrostrictive materials are sought after in high-precision displacement actuators due to their ultra-low hysteresis electrostrain. Here we report a very promising electrostrictive material by doping barium zirconate into a sodium potassium niobate matrix. Also, the dielectric behaviors and electrostrictive properties of (1-x)K_0.5Na_0.5NbO₃-xBaZrO₃ (x = 0.10, 0.12, 0.14 and 0.16) ceramics are investigated in details. The doping of barium zirconate allows the diffuse phase transition to occur near room temperature. Diffuse dielectric anomalies at high temperatures are observed in poled ceramics, which are closely related to the activation of defects. High electrostrain (∼0.1 %) with ultra-low strain hysteresis (< 12 %) are obtained at x = 0.14. Moreover, electrostrain exhibits excellent stability over a wide temperature range from 30 ℃ to 120 ℃.Further, the electrostrictive coefficient of ∼0.066 m⁴/C² for the component was determined at high temperatures and high electric fields, demonstrating the excellent potential of the K_0.5Na_0.5NbO₃-BaZrO₃ solid solutions as electrostrictive materials.