Ferroelectric properties of poly(vinylidenefluoride-trifluoroethylene) copolymer thin films

Abstract

The ferroelectric, piezoelectric, and pyroelectric characteristics in thin films (0.5–2.5 μm thick) of a copolymer composed of 74 mol % vinylidenefluoride and 26 mol % trifluoroethylene have been studied. They maintain remarkable ferroelectricity similar to that found in the thicker films of this copolymer. Both the temperature dependence of the reciprocal dielectric constant 1/ε and the biasing field dependence of the phase transition temperature Tc indicate the phase transition to be of a first order. A large pyroelectric coefficient (35–50 μC/m2 K) and the significant piezoelectricity related to e33 have been found in thin films of this copolymer.