Low-temperature sintering Sm-doped PMN–PZ–PT multilayer ceramic actuator with high strain and temperature stability

Multilayer ceramic actuators find extensive utility in applications requiring precise displacement control or force output, due to their advantages of high precision control, rapid response, low driving voltage, low power consumption, and so on. For practical applications, there is a need for high-performance multilayer ceramic actuators (MLAs) that combine cost-effectiveness, efficiency, and temperature stability. In this work, 1.5 mol%Sm-doped 0.25 Pb(Mg 1/3 Nb 2/3 )O 3 –0.36PbZrO 3 –0.39PbTiO 3 piezoelectric ceramics with PbO–CuO as sintering aid were fabricated. The addition of PbO–CuO significantly reduced the sintering temperature by 300°C, while having minimal impact on the piezoelectric properties. The optimized sintering condition, achieved at a low sintering temperature of 950°C with the introduction of a tiny 0.4 wt% sintering aid, yields impressive piezoelectric strain coefficient d 33 * = 690 pm/V. This substantiates the viability of employing low-cost Ag/Pd (90/10) as inner electrode, which can be co-fired with ceramic layer to fabricate MLA. This innovation enables a remarkable displacement of 1 µm at a low driving voltage of 200 V across a 9-layers piezoelectric actuator, accompanied by high-temperature stability, exhibiting <20% variation over the temperature range of 30–250°C. These results underscore a great potential for high-performance piezoelectric actuators over a broad temperature range.