Excellent strain properties in (K,Na)NbO3-based piezoceramics induced by lamination composite strategy

Abstract

To reconcile the contradiction between piezoelectric property and its temperature stability, the preparation of composite piezoceramics using multiple components has become an emerging direction. Herein, (K,Na)NbO3-based piezoceramics are adopted to prepare high-performance laminated composite ceramics inspired by the lamination composite strategy, and sintered in the reducing atmosphere to meet the development of multilayer piezoelectric actuators with base metal internal electrodes. By adjusting the composition ratio, a high inverse piezoelectric coefficient d33* of 1065 pm/V (@ 2 kV/mm) is obtained in the two-component composite ceramics, which fluctuated less than ± 6% in the range of 25–160 °C. In the three-component composite ceramics, a higher d33* value of 1326 pm/V (@ 2 kV/mm) is achieved and maintained > 90% until 150 °C. The electric-field-induced strain performances of laminated composite ceramics significantly exceed those of their basic components, which is related to the piezoresponse gain provided by the internal interfaces. The excellent temperature stabilities come from the more diffused phase transition temperature range formed by the complementation of multiple components. The combination of ultrahigh strain performance, high temperature stability, and good fatigue resistance, together with sintering in the reducing atmosphere, constitutes an important step to promote the application of (K,Na)NbO3-based multilayer piezoelectric actuators.