Structure and Electrical Properties of 0.85NaNbO 3 -0.15LiNbO 3 Ceramics

Structure and electrical properties of () ceramics were investigated as a function of sintering temperature. ceramics were prepared by conventional solid state processing. A main phase of the orthorhombic perovskite structure and secondary phase of were confirmed for all sintered specimens. Dense ceramics were obtained at sintering temperature above . With increasing sintering temperature, the electromechanical coupling factor (), piezoelectric constant () and relative dielectric constant () of the sintered specimens increased, while the mechanical quality factor () decreased. These results are due to the increase of grain size and crystallite size of orthorhombic perovskite structure. Based on the temperature dependence of , stable piezoelectric properties were expected because no phase transition found up to . Typically, kp of 18%, of 34.7 pC/N, of 135, and of 62.8 were obtained for the specimens sintered at for 5 h.