Threshold fields in the dc bias dependence of dielectric responses of relaxor ferroelectric terpolymer films

The dc bias dependence of dielectric properties has been investigated for poly (vinylindene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor terpolymer films. The frequency dependence of the temperature of the permittivity maximum, T-m, was analyzed using the Vogel-Fulcher (VF) relation. Two threshold fields, similar to 30 and 160 MV/m were found in the electric-field dependence of T-m. T-m shows a minimum at similar to 30 MV/m and a maximum at similar to 160 MV/m. The VF parameters activation energy E-a and freezing temperature T-f respectively show a maximum and a minimum at similar to 25 MV/m. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3259375]