Structure and electrical properties of new Pb(Zr,Ti)O₃- Pb(Fe_{2 / 3}W_{1 / 3})O₃-Pb(Mn _{1 / 3}Nb_{2 / 3})O₃ ceramics

A new piezoelectric material, Pb(Zr,Ti)O₃-Pb(Fe _{2 / 3}W_{1 / 3})O₃-Pb(Mn_{1 / 3}Nb _{2 / 3})O₃ (PZT-PFW-PMN) ceramics, was prepared by conventional mixed-oxide method. Effects of Pb(Fe_{2 / 3}W _{1 / 3})O₃ (PFW) content on phase structure, microstructure, dielectric and piezoelectric properties of PZT-PFW-PMN ceramics were studied. It indicates that substitution of Pb(Fe_{2 / 3}W_{1 / 3})O ₃ is effective on forming the solid solution and inhibiting the formation of pyrochlore phase. The proper addition of Pb(Fe _{2 / 3}W_{1 / 3})O₃ can promote the grain growth of the ceramics and make the ceramics have a high density. The dielectric and piezoelectric properties are also enhanced by adding Pb(Fe_{2 / 3}W _{1 / 3})O₃ into PZT-PMN. The 0.90PZT-0.03PFW-0.07PMN ceramics exhibit optimized properties. The dielectric and piezoelectric properties of this composition are as follows: d₃₃ = 358 pC/N, K _p = 0.63, Q_m = 1655, tanδ = 0.0053, ε_r = 1745 and T_c = 273 °C, which show that this system is a new promising material for high power piezoelectric transformers application.