TITLE:
Structure and Electrical Properties of Oxide Doped Rhombohedral Pb(Ni1/3Nb2/3)O3-PbTiO3 Ferroelectric Ceramics
AUTHORS:
Bijun Fang, Dun Wu, Qingbo Du, Limin Zhou, Yongyong Yan
KEYWORDS:
Lead Nickel Niobate-Lead Titanate, Perovskite, Dielectric Property, Ferroelectric Property, Piezoelectricity Property
JOURNAL NAME:
Materials Sciences and Applications,
Vol.1 No.2,
June
30,
2010
ABSTRACT: 0.7Pb(Ni1/3Nb2/3)O3-0.3PbTiO3 (0.7PNN-0.3PT) and 1 mol% La2O3-, Y2O3-, ZnO-, MnO2- and Nb2O5-doped 0.7PNN- 0.3PT ferroelectric ceramics were prepared by the conventional solid-state reaction method via the columbite precursor route. The ceramics sintered at 1180℃ exhibit pure rhombohedral perovskite structure except the Y2O3-doped 0.7PNN-0.3PT ceramics. The oxide-doped 0.7PNN-0.3PT ceramics exhibit rather homogeneous microstructure and improved densification, especially for the MnO2-and La2O3-doped 0.7PNN-0.3PT (defect) ceramics whose relative density is larger than 96%. All the above dopants decrease the dielectric loss of the 0.7PNN-0.3PT ceramics, whereas the values of the dielectric maximum (?m) and the temperature of ?m (Tm), and the character of dielectric response vary differently. ZnO and Nb2O5 doping increase remanent polarization Pr, and La2O3, ZnO, MnO2 and Nb2O5 doping decrease coercive field Ec of the 0.7PNN-0.3PT ceramics. Piezoelectric property is greatly improved by Y2O3, MnO2, Nb2O5 and ZnO doping, where the MnO2-doped 0.7PNN-0.3PT ceramics exhibit the largest value of piezoelectric constant d33, which reaches 191 pC/N.