The Strong Dependence of Polarization Fatigue on Poling-Voltage Conditions in Ferroelectric Vinylidene Fluoride and Trifluoroethylene Copolymer Films

Recently, polarization fatigue in ferroelectric polymers has attracted much attention due to their potentials in nonvolatile memory devices, although the mechanism behind is still an open question. In this letter, we report the strong dependence of polarization fatigue on poling voltages, which indicates that the application of a poling electric field slightly below the coercive field can greatly degrade the fatigue endurance. This phenomenon may be directly related to the fatigue mechanism, and its origin is discussed based on the understanding of the injection and redistribution of space charges in ferroelectric films.