The ferroelectric crystallites in the copolymer are transformed to nonpolar crystallites in the terpolymer after introducing the CFE defects. This is also evident in their corresponding X-ray diffraction patterns provided in Fig. 4. The ferroelectric P(VDF-TrFE) copolymer displays a diffraction peak at 2θ=20.1◦ (originating from the (110,200) reflection and corresponding to a lattice spacing of 4.417 Åin ferroelectric crystalline phases). This peak shifts to lower diffraction angle (18.3◦) for the P(VDF-TrFE-CFE) terpolymer, indicating a larger lattice spacing of 4.848 Å(from the (110, 200) reflection in nonpolar crystallites) [11, 15]. The non-polar nature of the terpoly-mer crystallites is also supported by the disappearance of the F-P transition in the DSC thermogram, compared with the strong ferroelectric-paraelectric transition exhib-ited by ferroelectric P(VDF-TrFE) copolymers (∼100◦C