Lead-free (K, Na)NbO3-Bi0.5K0.5ZrO3-BaZrO3 ternary system: Microstructure and electrical properties

In this work, new (K, Na)NbO3 ternary system {e.g., (1−x) (0.96K0.48Na0.52(1+3/995)NbO3-0.04Bi0.5K0.5ZrO3)-xBaZrO3} lead-free piezoceramics have been prepared by the conventional solid state sintering method, and effects of BaZrO3 contents on their microstructure and electrical properties were investigated in detail. The rhombohedral-orthorhombic and orthorhombic-tetragonal phase coexistence has been found in the ceramics with the composition range of 0.0125 < x ⩽ 0.02, and then the ceramics with x = 0.0175 exhibit enhanced electrical properties (e.g., d33 = 305 pC/N, kp = 49.5%, εr = 1945, tan δ = 3.9%, Pr = 22.5 μC/cm2, and EC = 10.2 kV/cm). In addition, such a ceramic possesses a high Curie temperature (TC = 300 °C). These results show that this material should be one of the most promising lead-free candidates for piezoelectric applications.