Dielectric and piezoelectric properties of low-temperature-sintering Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics for multilayer piezoelectric actuator

In this study, in order to develop low-temperature-sintering ceramics for a multilayer piezoelectric actuator, Pb(Mg-1/2-W-1/2)O-3-Pb(Ni1/3Nb2/3)O-3-Pb(Zr,Ti)O-3 (PMW-PNN-PZT) ceramics were fabricated using Li2CO3 and CaCO3 as sintering aids and their dielectric and piezoelectric properties were investigated in relation to the amount of Bi substitution. Piezoelectric actuators require both a high piezoelectric constant (d(33)) and a high electromechanical coupling factor (kp). Accordingly, in this study, Bi was substituted at the Pb site of basic composition PMW-PNN-PZT ceramics for the enhancement of kp and d33. With increasing Bi substitution, density gradually increased. At the sintering temperature of 900 degrees C, the electromechanical coupling factor (kp) and piezoelectric constant (d(33)) of PMW-PNN-PZT composition ceramics with 1.0 mol% Bi substitution as well as 0.2 wt % Li2CO3 and 0.25 wt % CaCO3 showed the optimal value of 0.618 and 473 pC/N, respectively, for multilayer piezoelectric actuator application.