Large electric tunability in poly(vinylidene fluoride-trifluoroethylene) based polymers

A tunability as high as 86% was obtained at the Curie temperature in poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] 55/45 copolymers when a 100 MV/m dc electric field was applied. The tunability was much higher than that in P[VDF-TrFE-chlorofluoroethylene (CFE)] 64.3/27.6/8.1 terpolymers, which demonstrated only 49% in a 50 MV/m electric field and at the phase transition temperature. The large difference was regarded to come from the domain size change when CFE was introduced into the copolymers, and the polymer changed from normal ferroelectric for copolymers to the relaxor ferroelectric for terpolymers. (C) 2008 American Institute Physics.