Preparation of PZN–PT–BT ferroelectric ceramics by modified two-step method

Based on the columbite route proposed by Swartz and Shrout, pure perovskite 75Pb(Zn1/3Nb2/3)O3–10PbTiO3–15BaTiO3 solid solution ceramics are synthesized by the modified two-step method. The ZnNb2O6 and PbO by the molar ratio 1:3.05 were ball-milled and then pre-reacted at 660 °C for 1–2 h. This pre-reacted mixture was wet mixed with the corresponding amounts of PbO, TiO2 and BaCO3 powders, and ball-milled and dried again. Then, the samples were sintered in a double sealed Al2O3 crucible at temperature ranging from 1060 °C to 1140 °C for 2 h. Although there is not any perovskite phase in the precursor powder analyzed by X-ray diffraction (XRD), the ceramics specimens sintered at temperatures from 1060 °C to 1140 °C for 2 h were 100% perovskite phase. The dielectric properties of 75Pb(Zn1/3Nb2/3)O3–10PbTiO3–15BaTiO3 ceramics were discussed in terms of sintering temperature and soak time.