Effect of SrZrO3 on phase structure and electrical properties of 0.974(K0.5Na0.5)NbO3–0.026Bi0.5K0.5TiO3 lead-free ceramics

(0.974−x)(K0.5Na0.5)NbO3–0.026Bi0.5K0.5TiO3–xSrZrO3 lead-free piezoelectric ceramics have been prepared by the conventional solid state sintering method. Systematic investigation on the microstructure, crystalline structures as well as electrical properties of the ceramics was carried out. With the addition of SrZrO3, the rhombohedral–orthorhombic phase transition temperature of the ceramics increases. Both the rhombohedral–orthorhombic and orthorhombic–tetragonal phase transitions of the ceramics were modified to be around room temperature when x~0.05, and as a result remarkably strong piezoelectricity has been obtained in 0.924(K0.5Na0.5)NbO3–0.026Bi0.5K0.5TiO3–0.05SrZrO3 ternary system, whose piezoelectric parameters were d33=324 pC/N and kp=41%.