Phase structure-electrical property relationships in Pb(Ni_(1/3)Nb_(2/3))O_3-Pb(Zr,Ti)O_3-based ceramics

摘要

Generally, the phase structure change of Pb(B' B")O_3-PZT solid solutions near a morphotropic phase boundary (MPB) can be originated from composition variations. Here our results show that the excess PbO and the sintering temperature can also result in the ferroelectric phase structure change in the Pb(Ni_(1/3)Nb_(2/3))O_3-Pb(Zr,Ti)O_3 (PNN-PZT)-based ceramics near the MPB. The dielectric, piezoelectric, and ferroelectric properties are dependent on the tetragonal phase content (TP) which is closely associated with the excess PbO and the sintering temperature. The temperature dependence of the polarization (P)-electric field (E) hysteresis loops reveals that the tetragonal phase in the PNN-PZT-based ceramics has a lower activation energy (E_a) for domain wall movement than that of the rhombohedral phase, thus resulting in easier polarization rotation. This is responsible for the phase structure-electrical property relationships in the PNN-PZT-based ceramics, exhibiting the dependence of the tetragonal phase content (TP) on the electrical properties.