Influence of Uniaxial Pressure on Dielectric Properties and Aging Effect of BiFeO 3 Ceramic.

The external stress (0–1500 bar) dependence of dielectric properties and an aging effect of BiFeO3ceramic has been investigated. The electric permittivity and dielectric losses first increased (up to about 700 bar) and next decreased with uniaxial pressure applied parallel to the ac field direction, while increased with the stress perpendicularly applied. It was suggested that combination of the de-aging, clamping of the domain walls, and the polarization reorientation mechanisms can be responsible for these changes. The aging effect is followed logarithmic law and is related to the relaxation of the domain structure towards an equilibrium configuration. [ABSTRACT FROM AUTHOR]