High-power properties of piezoelectric hard materials sintered at low temperature for multilayer ceramic actuators

0.05Pb(Mn1/3Sb2/3)O3–0.05Pb(Al1/2Nb1/2)O3–0.9Pb(Zr0.48Ti0.52)O3 (PMS–PAN–PZT) high power piezoelectric system with both La2O3 as a hardener and CuO as a low sintering agent had been synthesized at 900 °C for 2 h. When La2O3 doping of the main composition went over 0.5 wt%, the mixed tetragonal and rhombohedral perovskite structure changed to pure rhombohedral perovskite structure. In case of the CuO, 1.0 and 1.5 wt% CuO content significantly improved the sinterability of the PMS–PAN–PZT system processed at 900 °C for 2 h. When La2O3 and CuO co-doped in PMS–PAN–PZT ceramics, piezoelectric constants (d33), quality factor (Qm), electromechanical coupling factor (kp) and dielectric constant ( ε 3 T / ε 0 ) of the piezoelectric ceramics sintered at 900 °C for 2 h were optimized, such as 336 pC/N, 841, 60%, and 1358, respectively. New developed piezoelectric materials are promising for high power multilayer ceramic actuators.