Phase structure and electrical properties of (K0.5Na0.5)NbO3–(Bi0.5Na0.5)ZrO3 lead-free ceramics with a sintering aid of ZnO

0.95(K0.5Na0.5)NbO3–0.05(Bi0.5Na0.5)ZrO3–xZnO (KNN–BNZ–xZnO) lead-free piezoceramics were prepared by the conventional solid-state method, and effects of ZnO content on their phase structure, microstructure, and electrical properties were studied. The ceramics with x=0.01 possess the mixture of both rhombohedral–orthorhombic and orthorhombic–tetragonal phase boundaries. Their grain size becomes more homogenous and much smaller with the addition of ZnO. Enhanced dielectric and piezoelectric properties (e.g., d33=320 pC/N, kp=0.484, TC=320 °C) were observed in the ceramic with x=0.01. These results show that such a material system belongs to be a promising lead-free piezoelectric material.