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

Abstract (0.974− x )(K 0.5 Na 0.5 )NbO 3 –0.026Bi 0.5 K 0.5 TiO 3 – x SrZrO 3 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 SrZrO 3 , 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(K 0.5 Na 0.5 )NbO 3 –0.026Bi 0.5 K 0.5 TiO 3 –0.05SrZrO 3 ternary system, whose piezoelectric parameters were d 33 =324 pC/N and k p =41%.