Dynamic response of the dielectric and electro-optic properties of epitaxial ferroelectric thin films

Abstract

An analysis of the dynamic dielectric and electro-optic relaxation response of thin-film ferroelectrics is presented. The analysis is based upon the relaxation of ferroelectric domains with a continuous distribution of sizes given by percolation theory. The resulting temporal response is described by the expression $\Phi \mathrm{}\left(t\right)\mathrm{}\propto t^{-m}\exp \left[-\right(t/\tau {)}^{\beta }].$ The analysis was applied to ${\mathrm{KNbO}}_3$ thin films. Measurements of the polarization, birefringence, and dielectric transients show qualitative agreement with the model over 11 orders of magnitude in time.