Preparation and Property of (Na_0.52K_0.44Li_0.04)(Nb_0.9Sb_0.04Ta_0.06)O₃ Piezoelectric Ceramics and Ceramic Buzzer

(Na_0.52K_0.44Li_0.04)(Nb_0.9Sb_0.04Ta_0.06)O₃ piezoelectric ceramics with size of φ15 mm×0.1 mm was prepared by solid-state sintering method, and then the microstructure, electrical property and thermal depolarization property of the ceramics were studied. The ceramics were packaged into a buzzer and the acoustic property of the buzzer was measured and compared with that of the commercial lead-based one. The results show that the ceramics had the pure perovskite phase (tetragonal) structure. Below the Curie temperature (265℃), the piezoelectric constant were about 280 pC·N^-1 and reached 89.2% that of the unheating ceramics, indicating the good temperature stability. The sound pressure level of the buzzer made of the ceramics was slightly lower under the conditon of (1-4) kHz/9 V while better under the condition of 2 kHz/3 V than that of the lead-based one. Moreover, the acoustic property of the ceramic buzzer kept stable at temperatures between -40℃ and 85℃.