The effect of oxygen vacancy on the dielectric and electromechanical properties in

lead titanate zirconate based ferroelectric ceramics was considered. The presence

of oxygen vacancy forms a defect-dipole inside a perovskite cell. This defectdipole

contributed to the unswitchable polarization and influences the alignment of

the ferroelectric dipole in the same cell as well. The latter was due to the

displacement of the B-site cation, which contributed to the switchable polarization.

It was found that a double hysteresis emerges when the alignment of defect-dipole

conforms with the crystal orientation, which was perpendicular to the measured

polarization. Moreover, the optimal electromechanical property can be obtained by

careful adjustment of c-domain volume fraction and the alignment of defect

dipoles. Monte Carlo simulation based on the four-state Potts model was presented.

Calculation results were compared with experiments.

Investigating the Effect of Oxygen Vacancy on the Dielectric and

Electromechanical Properties in Ferroelectric Ceramics. V.Lo, W.W.Chung,

H.Cao, X.Dai: Journal of Applied Physics, 2008, 104[6], 064105