Nonlinear conductivity of ion-complexed polyethylene oxide

The electric polarization in polyethylene oxide com-plexed with LiClO4 has been investigated over the frequency range from 10 mHz to 10 kHz. The exciting electric fields have been chosen so high that nonlinear components in the dielectric response are evident. Nonlinear dielectric and conductive spectra are determined and their temperature dependence is studied. It is found that the nonlinear relaxation shows a temperature dependence similar to the linear relaxation. With rising temperature the phenomena shift to higher frequencies and the relaxation strength increases. To evaluate relaxation frequencies and strengths theoretical functions are fitted to the experimental data. While the linear spectra are reproduced well over the whole frequency range, a reasonable agreement between experimental data and theoretical curves is found in a limited frequency range only for the nonlinear spectra.