Chen X.,Sichuan Provincial Key Laboratory of Chemical Synthesis and Pollution Control |
Chen X.,China West Normal University |
Liao Y.,Sichuan Provincial Key Laboratory of Chemical Synthesis and Pollution Control |
Liao Y.,China West Normal University |
And 11 more authors.
Yadian Yu Shengguang/Piezoelectrics and Acoustooptics | Year: 2011
The lead-free piezoelectric ceramics Bi0.5(Na0.825K0.175)0.5 TiO3+xwt% Ag2O(BNKTA-x, x=0, 0.1, 0.3, 0.5, 0.7, 1.0, 1.5) were prepared by the conventional solid-state reaction process. The crystal phase, microstructure and dielectric properties of Ag-doped Bi0.5(Na0.825K0.175)0.5 TiO3 ceramics were investigated by means of X-ray diffraction(XRD), SEM. XRD analysis indicated that the pure perovskite structure could be obtained when x was less than 1.0% at the condition of the sintering temperature of 1175°C/2 h. All the grains were tetragonal with clear boundary and high surface density. The introduction of Ag promoted the growth of grains. Additionally, the porosity of the ceramic simple has been reduced by introducing Ag. When Ag was about 0.3%, the density of the ceramic was optimal. The BNKTA-x system ceramic had excellent electric properties with the piezoelectric constant d33 of 147 pC/N, the electromechanical coupling coefficient kp of 0.31, the dielectric constant εr of 1059, the dielectric loss tan δ of 0.029, and the mechanic factor Qm of 247.