Poling of polymer films with ferroelectric electrodes

A novel technique for the poling of polymer ferroelectrics and electrets is applied to polyvinylidene fluoride/trifluoroethylene (P(VDF-TrFE)) copolymers. The polymer film to be poled is pieced between the polished unmetallized surfaces of homogeneously polarized ferroelectric crystals (TGS, BaTiO₃) or ceramics (PLZT). Only the external surfaces of the ferroelectric electrodes are covered with metal. For the poling process the polarization of the ferroelectric electrodes is switched by an appropriate high voltage connected to the stack. The FEP (ferroelectric electrode poling) technique completely avoids destructive electric breakdown, a problem frequently occuring when polymer films are poled between metal electrodes. A high and uniform polarization is achieved in the copolymer films. The experiments show that charge injection front metal electrodes is not essential for the poling of P(VDF-TrFE) copolymers