Depolarization fields in thin ferroelectric films

Abstract
A mechanism is proposed to explain depolarization phenomena that have been observed in thin ferroelectricfilms and related multilayerdevices. It is shown that, for a short‐circuited electrode‐ferroelectric structure, incomplete compensation of the ferroelectricpolarization charge results when the center of gravity of this charge and the free compensation charge are not coincident. Depolarization fields in the ferroelectric arising from such incomplete compensations are estimated. A simple switching calculation shows such fields to be of sufficient strength to account for the initial polarization decay rate observed in Pb0.92Bi0.07La0.01 (Fe0.405Nb0.325Zr0.27)O3films. The results of measurements involving changes in film thickness, electron concentration in the electrodes, and contact materials will be discussed and shown to be consistent with the mechanism proposed.

This publication has 24 references indexed in Scilit: