Effect of Oxide Doping on Electrical Properties of Tetragonal Perovskite Pb(Ni1/3Nb2/3)O3-PbTiO3 Ferroelectric Ceramics

Abstract

Pure and 1mol% La2O3-, Y2O3-, ZnO-, MnO2- and Nb2O5-doped 0.58Pb(Ni1/3Nb2/3)O3-PbTiO3 (0.58PNN-0.42PT) ferroelectric ceramics were prepared by conventional ceramic processing via the columbite precursor route. XRD measurement confirmed that phase-pure tetragonal perovskites can be obtained in the pure and oxide-doped 0.58PNN-0.42PT ceramics sintered at 1180°C for 2 h except that the Y2O3-doped 0.58PNN-0.42PT ceramics contain slight content of pyrochlore phase. Oxide doping improves densification of the 0.58PNN-0.42PT ceramics, especially for the Y2O3-, ZnO- and MnO2-doped ones whose relative density is larger than 95%. Oxide doping decreases dielectric constant of 0.58PNN-0.42PT slightly accompanied by the decrease of the temperature of dielectric maximum (TC or Tm) and great broadening of the dielectric response peaks where frequency dependent dielectric behavior is apparent around the temperature range of Tm. All the oxide-doped 0.58PNN-0.42PT ceramics exhibit fat and nearly rectangular shape P-E hysteresis loops accompanied by large value of saturation polarization Ps. The Nb2O5-doped 0.58PNN-0.42PT ceramics exhibit the largest value of remanent polarization Pr of 19.43μC/cm2 and the La2O3-doped 0.58PNN-0.42PT ceramics exhibit the least value of coerce field Ec of 7.14kV/cm. Piezoelectric constant d33 of the 0.58PNN-0.42PT ceramics decreases slightly by oxide doping, where the La2O3-doped 0.58PNN-0.42PT ceramics exhibit the largest value of d33, being 298pC/N.