Piezoelectric and Dielectric Characteristics of (Na,K)(Nb,Sb)O3 Ceramics Doped with CoO

In this study, in order to develop lead free piezoelectric ceramics which have excellent temperature stability and high sinteribility for low loss multilayer piezoelectric actuator application, (Na,K)(Nb,Sb)O3 ceramics were fabricated and their piezoelectric and dielectric properties were investigated as a function of the amount of CoO addition. CoO addition improved sinterability, electromechanical coupling factor kp, piezoelectric constant d33 and dielectric constant epsilon r of the composition ceramics. At the 0.3 wt% CoO added composition, density, kp, d33, epsilon r and phase transition temperature showed the optimum values of 4.30 [g/cm3], 0.41, 211 [pC/N], 751 and 155 degrees C, respectively, for low loss multilayer piezoelectric actuator application.