Relaxor ferroelectric behavior in high-energy electron-irradiated poly(vinylidene fluoride-trifluoroethylene) copolymers

This paper presents experimental results showing that in a certain composit ion range and under a proper electron-irradiation treatment, a normal ferro electric poly(vinylidene fluoride-trifluoroethylene) copolymer can be conve rted into a material exhibiting many typical features of relaxer ferroelect rics, suggesting that this is a new class of relaxor ferroelectric material . Furthermore, the irradiated copolymer can generate giant electrostriction (approximate to 5%) with a high elastic energy density. The X-ray diffract ion results obtained from the irradiated copolymer under electric field, in dicate that the observed polarization and strain response's are mainly due to the local phase transformation from a nonpolar phase to a polar phase.