Reduced hysteresis of KNNS-BNKZ piezoelectric ceramics through the control of sintering temperature

The hysteresis of piezoelectric ceramics plays an important role in determining errors when they are applied in actuators. However, the relationships between the hysteresis characteristic, preparation process of the piezoelectric ceramic, and displacement error of the actuator have rarely been systematically studied. In this study, 0.9625(K0.48Na0.52)(Nb0.6Sb0.4)O3-0.0375Bi0.5(Na0.82K0.18)0.5ZrO3 (KNNS-BNKZ) ceramics were prepared via a solid-state reaction and sintered at 1140 °C, 1160 °C, and 1180 °C. Subsequently, the influence of sintering temperatures on the phase composition, microstructure, piezoelectric properties, and ferroelectric properties of the samples was studied. Furthermore, the factors affecting the hysteresis characteristics were systematically analyzed. The results showed that the ceramic sintered at 1140 °C possessed the smallest hysteresis with Hmax = 25% owing to its phase composition and microstructure. Additionally, linear regression of the displacement versus voltage was carried out and the corresponding equations were obtained. Finally, the hysteresis model of the ceramic sintered at 1140 ℃ was established and its error was determined to be less than 1.81%, which renders these ceramics suitable for application in high-precision actuators.