Conductivity-induced polarization buildup in poly(vinylidene fluoride)

During initial high-field poling of biaxially stretched poly(vinylidene fluoride) (PVDF) films, ferroelectric polarization continues to develop through times of five to six orders of magnitude longer than theoretically expected poling times. Considering a delayed poling process induced by a finite conductivity in the two phases of PVDF explains the effect. The fast poling component originates from the alignment of dipoles in the ferroelectric phase and is solely controlled by the electric field dependent switching time, while the second slow component is controlled by conductivity related charge accumulation at the interfacial boundaries whose time constant is governed by the Maxwell relaxation time. (C) 2002 American Institute of Physics.