The study of weak molecular movements in nonpolar materials by decorating the structure with space charge

The ac dielectric relaxation technique allows to investigate the molecular dynamics by studying the dipoles movement under ac field. The Thermally Stimulated Discharge Current technique allows to investigate the molecular dynamics by studying the dipoles movement under dc field. There is a permanent challenge to use electrical methods to characterize molecular movement in nonpolar materials. It is demonstrated in this paper that the Final Thermally Stimulated Discharge Current technique can be used to investigate the molecular movements in nonpolar dielectrics. By controlling the isothermal charging and/or discharging times the structure is 'decorated' with space charge trapped in different traps. During the heating of the sample two types of peaks have been observed. The apparent peak, located 5 to 30 K above the charging temperature, is appropriate to study space charge injection/movement/trapping/detrapping. The peaks for which the difference between the temperature of the maximum current of the peak and the charging temperature is higher than about 30 K can be used to study the weak molecular movements and structural transformation in nonpolar materials.