Nonlinear dielectric response of polymer system with coexisting ferroelectric and relaxor states

We report dielectric investigations of poly(vinylidene fluoride-trifluoroetylene), P(VDF-TrFE) copolymer, irradiated with high-energy electrons. While the ferroelectric copolymer is transformed into a relaxor system at high irradiation doses, our investigations, particularly nonlinear dielectric experiments, clearly evidence that at lower doses ferroelectric and relaxor states coexist in the P(VDF-TrFE). Nonlinear dielectric response furthermore reveals the nature of the ferroelectric phase transition, which is confirmed by the polarization measurements.