Dielectric relaxation in cobalt doped potassium chloride crystals

Abstract
Two peaks are observed in tan delta against frequency isothermals in cobalt doped potassium chloride crystals in the temperature range 100 degrees C to 200 degrees C and frequency range 102 Hz to 105 Hz. The low and high frequency peaks have been labelled as A and B, respectively. The logarithm of peak frequencies plotted against 1/T gave straight lines for both the peaks. The values of the activation energy calculated from the slope of the straight lines are 0.83+or-0.06 eV and 0.85+or-0.06 eV for the A and B peaks respectively. None of the A and B peaks were found to be due to Maxwell-Wagner losses or interfacial polarization.