Analysis by thermally stimulated currents of the frequency power-law domains of the dielectric loss

The analysis of complex peaks in the technique of thermally stimulated depolarization currents (TSDC) often makes use of a distribution of relaxation times. Here we suggest a different approach that emphasizes the manifestation, in the TSDC measurement, of the asymptotic power-law domains of the relaxation function in the frequency measurement. Calculations for the Cole - Cole response function show that the results of a typical TSDC experiment for systems showing time-temperature superposition contain information about the frequency response on both sides of the spectrum. The reason for this is that the equivalent frequency of TSDC measurements is only low in absolute terms, but not with respect to the system's relaxation time, which decreases rapidly during the temperature scan of a TSDC experiment. The analysis of the stretched exponential and Havrilak-Negami functions indicates that the TSDC technique is able to provide an accurate determination of the fractionary exponents of the loss peak.