Conductivity enhancement in polymer electrolytes on gamma irradiation

We expose PEO(1−x)–NH4ClO4(x) (with x = 0.16–0.26) to gamma irradiation with doses varying from 10 to 40 kGy. The change in ion-conductivity with irradiation is observed. The ion-conductivity goes through a maximum at 30 kGy. The enhancement is two orders of magnitude for the x=0.16 sample, but not significant for x higher than 0.20. An equivalent circuit is used to fit simultaneously the Cole–Cole plot and the real part of admittance vs. frequency plot. It is seen that the samples show an inductive loop at high frequency for low doses, where conductivity is low. This may be a result of the spiral coiling of the polymer molecules.