Large Piezoelectric Strain with Superior Thermal Stability and Excellent Fatigue Resistance of Lead-Free Potassium Sodium Niobate-Based Grain Orientation-Controlled Ceramics

摘要

Environment-friendly lead-free piezoelectric materials with high piezoelectric response and high stability in a wide temperature range are urgently needed for various applications. In this work, grain orientation-controlled (with a 90% 001 (c)-oriented texture) (K,Na)NbO3-based ceramics with a large piezoelectric response (d(33)*) = 505 pm V-1 and a high Curie temperature (T-C) of 247 degrees C have been developed. Such a high d(33)* value varies by less than 5% from 30 to 180 degrees C, showing a superior thermal stability. Furthermore, the high piezoelectricity exhibits an excellent fatigue resistance with the d(33)* value decreasing within only by 6% at a field of 20 kV cm(-1) up to 10(7) cycles. These exceptional properties can be attributed to the vertical morphotropic phase boundary and the highly 001 (c)-oriented textured ceramic microstructure. These results open a pathway to promote lead-free piezoelectric ceramics as a viable alternative to lead-based piezoceramics for various practical applications, such as actuators, transducers, sensors, and acoustic devices, in a wide temperature range.