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

Departmento de Ingeneria de Materials, (DIMAT), Facultad de Ingenieria, Universidad de Concepcion, Edmundo Larenas 270, Casilla 160 C, Concepcion, Chile

Corresponding author: ramamk@udec.cl

Received: 5 June 2006
Revised: 18 September 2006
Accepted: 4 October 2006
Published online: 13 December 2006

Abstract

The ferroelectric and piezoelectric properties of Ag doped xPb(Mg_1/3Nb_2/3)O₃-(1 − x) Pb(Zr_0.532Ti_0.468)O₃ 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 μm in 1 mole% Ag doped 0.7PMN-0.3PZT, while the apparent density continuously increased up to 7.89 gm/cm³ 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 (ε_RT = 3864) at room temperature and the dielectric permittivity at the Curie temperature (ε_Tc = 26826), respectively. The ferroelectric properties exhibited optimum values of P_r = 36.82 μC/cm² and P_s = 45.29 μC/cm² in 1 mole% Ag doped 0.7PMN-0.3PZT, respectively while the E_c showed a decreasing trend throughout the series. The piezoelectric properties (d₃₃ = 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.