Effect of interfacial charge on polarization switching of lead zirconate titanate particles in lead zirconate titanate/polyurethane composites

A simple model has been developed to include the effect of accumulated charge at the matrix–inclusion interface in ferroelectric 0–3 composites on the polarization reversal characteristics. This is used to illustrate a recent set of experimental results on initially polarized lead zirconate titanate (PZT)/polyurethane (PU) composites subjected to an increasing electric field in the reversed direction. Estimations based on previous models [e.g., T. Furukawa, K. Fujino, and E. Fukada, Jpn. J. Appl. Phys. 15, 2119 (1976)] suggest that the local electric field in the PZT particles at switching was an order smaller than the coercive field of PZT. By introducing the effect of interfacial charge and assuming that initially the charge has a magnitude which balances the depolarization field in the polarized PZT inclusions, theoretical calculation based on this image shows that the phenomenon of PZT switching at low fields can be explained as a manifestation of the depletion of interfacial charge which can no longer stabilize the original polarization.