Effect of ZnO on Low Temperature Sintering of Pb(Mn1/3Nb2/3)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr1/2Ti1/2)O3 Ceramics

In this study, in order to develop the composition ceramics for low loss multilayer ceramic actuator for ultrasonic nozzle and ultrasonic vibrator applications, Pb(Mn_1/3Nb_2/3)O₃Pb(Ni_1/3Nb_2/3)O₃Pb(Zr_1/2Ti_1/2)O₃ (abbreviated as PMN-PNN-PZT) ceramics were fabricated using Li₂CO₃, Na₂CO₃ and ZnO as sintering aids. And then, their piezoelectric and dielectric properties according to the amount of ZnO addition were investigated. The addition of ZnO improved density, dielectric constant, electromechanical coupling factor, mechanical quality factor and piezoelectric d constant of PMN-PNN-PZT ceramics due to the increase of sinterability and accepter doping effect. Electromechanical coupling factor(kp) and mechanical quality factor(Q_m) of PMN-PNN-PZT ceramics increased with ZnO amount up to 0.4 wt% and then decreased. At the sintering temperature of 900degC and 0.4 wt% ZnO addition, density, dielectric constant, electromechanical coupling factor(k_p), mechanical quality factor(Q_m) and piezoelectric d₃₃ constant showed the optimum value of 7.876 g/cm³, 1299, 0.612, 1151 and 369 pC/N, respectively, for low loss multilayer ceramic actuator application.