Ferroelectric and piezoelectric properties of Ag modified PMN-PZT solid solutions

The ferroelectric and piezoelectric properties of Ag doped xPb(Mg1/3Nb2/3)O3-(1 - x) Pb(Zr0.532Ti0.468)O-3 ceramics, for Ag = 0.5, 1 and 1.5 mole%, synthesized by the columbite precursor method were investigated. The experimental results indicate that stoichiometry plays a significant role in the solubility of Ag and it affects the physical properties. The factors influencing microstructural development of Ag doped PMN-PZT are the Ag and PMN concentrations and Ag diffusion during the sintering process as can be observed from the scanning electron micrograph. Grain growth is considerably enhanced up to 4.05 mu m in 1 mole% Ag doped 0.7PMN-0.3PZT, while the apparent density continuously increased up to 7.89 gm/cm(3) in 1 mole% Ag doped 0.8PMN-0.2PZT, respectively. It was observed that 1 mole% Ag doped 0.7PMN-0.3PZT attained maximum values for the dielectric permittivity (epsilon(RT) = 3864) at room temperature and the dielectric permittivity at the Curie temperature (epsilon(Tc) = 26826), respectively. The ferroelectric properties exhibited optimum values of P-r = 36.82 mu C/cm(2) and P-s = 45.29 mu C/cm(2) in 1 mole% Ag doped 0.7PMN-0.3PZT, respectively while the E-c showed a decreasing trend throughout the series. The piezoelectric properties (d(33) = 297 pC/N and k(p) = 0.377) were enhanced in 1 mole% Ag doped 0.4PMN-0.6PZT and 0.7PMN-0.3PZT, respectively.