Effect of SiO₂-Li₂O₃-CuO additive on piezoelectric properties of PMS-PZT ceramics at low sintering temperature

Lead zirconate titanate (PZT) based piezoelectric ceramics are applied in ultrasonic transducers and multilayer actuators fields universally. Excellent piezoelectric properties of PZT-based ceramics of low sintering temperature are crucial for the applications of high-power motors and multilayer piezo-actuators due to the reduction of cost and energy consumption. In this paper, a ternary solid-solution ceramic system 0.05Pb(Mn_1/3Sb_2/3)O₃-0.47PbZrO₃-0.48PbTiO₃ (PMS-PZT) was studied. A new complex additive composed of SiO₂-Li₂O₃-CuO was doped into the PMS-PZT ceramics. The doping of CuO and Li₂O₃ was discovered to be able to lower the sintering temperature and remain electric properties efficiently, while the doping of SiO₂ can decrease the grain size and increase the density. All ceramic samples were fabricated by solid-phase reaction method and sintered in the low temperature range from 800 °C to 1000 °C. The phase structure, morphology of natural surface and electrical properties of ceramics doped by 0.5 wt% additive were characterized. The 0.5 wt% additive doped PMS-PZT ceramics exhibit remarkable comprehensive piezoelectric properties sintered at 900 °C (d₃₃ = 343 pC/N, Q_m = 1016, T_c = 328 °C, tanδ = 0.4 % (at 25 °C), ε_r = 1344, d₃₃* = 490 pm/V). The sintering temperature 900 °C is significantly below the melting point of Ag (961.9 °C) and Cu (1083.4 °C), so the more cost-effective Cu internal electrodes and Ag rich Ag/Pd electrodes can be used to substitute the expensive Pd rich Ag/Pd internal electrodes in the production of devices composed of multilayer ceramic. The research of this work provides an important candidate additive for the applications of high-performance transducers and multilayer actuators with low cost.