For the terpolymer investigated here, there is no sign in the dielectric spectra of an F-P transition (Fig. 12). There is no hysteresis in the dielectric data when mea-sured in heating and in cooling. On the other hand, for terpolymers with lower CFE concentration or nonuniform CFE distribution in the terpolymer, large coherent polar-domains and a relaxor phase coexist, and a frequency-independent phase transition process is ob-served in both ε and ε spectra, although it is shifted to lower temperatures [17]. In previous studies on high-energy electron irradiated copolymers,similar incomplete normal-relaxor conversion has also been observed in samples with insufficient irradiation treatment of the P(VDF-TrFE) copolymer [7, 8, 34]. However, increasing the ir-radiation dosage eliminates the ferroelectric phase in the copolymer and hence there is no sign of F-P phase transition process in the dielectric spectra in these properly treated copolymers [7].