Phase transition investigation in vinylidene fluoride/trifluoroethylene copolymers by thermally stimulated conductivity measurements

An additional ferroelectric phase transition, beside the well-known ferro-to-paraelectric one, was detected in vinylidene fluoride/trifluoroethylene copolymers by thermally stimulated techniques with the help of a superimposed piezoelectric noise. Differential scanning calorimetry measurements were in agreement with these results. With the initial rise method applied to the glow curves, it was possible to calculate the activation energies of the relaxation connected with both transitions. The authors found 0.73 eV and 0.33 eV, respectively, for the ferro-to-paraelectric and the additional phase transitions