Influence of sintering temperature on structure and properties of V_2O_5-doping KNN-LS-BF piezoelectric ceramics

摘要

0.6 mol % V_2O_5-doping 0.996(0.95Na_(0.5)K_(0.5)NbO_3-0.05LiSbO_3)-0.004FeBiO_3 ((KNN-LS-BF)-V_2O_5) piezoelectric ceramics were synthesized by the conventional solid-state reaction process. The influence of sintering temperature on structure and properties of (KNN-LS-BF)-V_2O_5 ceramics were studied. The results show that the sintering temperature has significant influence on crystal structure, density and properties. The specimens sintered at 1040-1100 ℃ all are perovskite structure mixed with orthorhombic symmetry phase and tetragonal phase, but the crystal lattice constant and the grain size both become smaller as the sintering temperature increasing. With the increase of sintering temperature, the d_(33), k_p, ε_r, tanδ, Q_m exhibit different variation trend and have been improved obviously due to the enhance in density when the sintering temperature is 1080 ℃, but too high sintering temperature would degrade their k_p and tanδ. The (KNN-LS-BF)-V_2O_5 ceramics with the optimum combination properties can be synthesized at 1080 ℃, relating constants as d_(33) = 161pC/N, k_p = 0.30, ε_r = 1057, tanδ = 3.92 %, Q_m = 58.95, respectively.