Electrostriction and Piezoelectricity in Ferroelectric Polymers

The effect of electrostriction on piezoelectric activity has been investigated in a ferroelectric copolymer of vinylidene fluoride and trifluoroethylene with a composition of 52/48 mol%. The electrostriction constants determined from changes in lattice spacing and the spontaneous polarization associated with a ferroelectric-to-paraelectric transition induce piezoelectric activities, positive d31 and negative d32. The combined contributions from the dimensional effect and the electrostrictire coupling are consistent with the magnitude and anisotropy of observed piezoelectric constants.