Phase structure and electrical properties of (K_(0.5)Na_(0.5))NbO_3-(Bi_(0.5)Na_(0.5)) ZrO_3 lead-free ceramics with a sintering aid of ZnO

摘要

0.95(K_(0.5)Na_(0.5))NbO_3-0.05(Bi_(0.5)Na_(0.5)) ZrO_3-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., d_(33)=320pC/N, k_p=0.484, T_c=320℃) 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.