Tunable temperature dependence of electrocaloric effect in ferroelectric relaxor poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene terpolymer

The electrocaloric effect (ECE) was directly measured in a relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer. It was observed that the temperature dependence of ECE of the terpolymer films depends critically on the film preparation conditions. While the uniaxially stretched terpolymer films show pronounced temperature dependence of ECE, the non-stretched films exhibit nearly temperature independent ECE from 5 °C to 45 °C. Such a difference is likely caused by the changes in possible polar states and polar-correlation range by film stretching. Besides, large ECE (T > 15 °C) can be induced in both films at 30 °C and 150 MV/m.