Use of the final thermally stimulated discharge current technique to analyze space charge behavior in dielectrics

The final thermally stimulated discharge current technique is proposed for analyzing space charge (SC) trapping/detrapping. The letter investigates the effects associated with SC behavior in polyamide 11 in an attempt to discriminate between dipolar and SC related effects. An apparent peak, located 5–13 °C above the charging temperature, and a second peak around 96 °C were observed. Both peaks scale linearly with the field revealing a similar behavior of dipolar and interfacial polarization. The peaks position and the apparent activation energy W do not change with the charging field, but are very sensitive to the previous charging/discharging times. A distribution of the apparent activation energies in a range from 0.45 to 2.20 eV is revealed for the apparent peaks. The isothermal decay of SC at 35 °C is proportional to log t, a behavior that may be characteristic for the interfacial polarization.