OPEN-CIRCUIT AND SHORT-CIRCUIT THERMALLY STIMULATED CURRENTS IN ETHYLCELLULOSE

Thermally stimulated currents (TSCs) in short-circuit and open-circuit configuration for ethyl cellulose samples (approximate to 40 mu m thi ck) have been studied as a function of polarizing field (25-100 kV/cm) and polarizing temperature (323-353 K). The thermograms have been fou nd to be characterized by two prominent peaks located around 70 +/- 10 degrees C and 140 +/- 10 degrees C and the appearance of anomalous cu rrent in the high temperature region of the short-circuit TSC thermogr ams. The observed behaviour has been explained in terms of the existen ce of heterocharge due to dipole orientation and ionic homocharge drif t, together with the injection of charge carriers from electrodes and their subsequent localization in surface and bulk traps.