A rational designed multi-layered structure to improve the temperature stability of Li modified (K,Na)NbO₃ piezoceramics

The temperature dependent properties of (K,Na)NbO₃-based piezoelectric materials enlightened us that the combination of compositions gradient could remedy the fluctuation of the electrical properties induced by the temperature variation. Then Li modified (K,Na)NbO₃ ceramics was chosen as target materials and a multi-layered structure containing a series of composition gradient layers was prepared via a conventional solid state reaction. The results of relative permittivity against temperature demonstrated that the as-called relaxor feature was observed in this proposed multi-layered structure and the change rate of the dielectric anomaly peak got evidently reduced. Besides, the field-induced strain varying less than 10% from the room temperature to 100 °C was also achieved in this layered-structure ceramics. Moreover, the investigation here could render us an important reference for designing ferroelectric materials to satisfy the diversified requirements in the functional device.