Dielectric Relaxation Behavior of C5+ (70 MeV) Swift Heavy Ion Irradiated Polyetheretherketone (PEEK) using TSDC Technique

The dielectric relaxation characteristics of polyetheretherketone (PEEK) irradiated with C5+ (70 MeV) ion, have been investigated in the temperature range 60-230 degrees as a function of poling temperature T-P (50, 100, 150, and 200 degrees C), poling field E-P (200, 300, 400, and 500 kV/cm), and storage time t(s) (2, 24, 48, and 120 h), using thermally stimulated discharge current (TSDC) technique. The TSDC spectra show a prominent maximum around glass transition temperature (T-g similar to 143 degrees C) named as alpha-peak. This peak is attributed to the movement of ketone dipoles linked with the main chain. It is observed that the magnitude of alpha-peak increases with the increase in poling temperature and poling field. The peak current and area under the alpha-peak are found to be diminished with the increase of storage time t(s) for electrets. The beta-peak (space charge peak) is absent in irradiated PEEK samples as compared to pristine PEEK samples. The results obtained, in the present studies, are compared with the results on pristine samples. The activation energies and pre-exponential factor for PEEK samples determined using Bucci plot method.