Depolarization current at high temperature by migration of space charge

The author presents results obtained by a modified method of thermally stimulated depolarizing current of a polymer electret, i.e., after raising the temperature just under the liquidizing point of test material, one keeps temperature constant and continues measurement of current. There were peaks in a graph of current vs. time by depolarization of an electret of a polymer, e.g., polyethylene terephthalate. A sharp peak at the turning point of temperature and a broad peak which appears after the temperature is kept constant were found. These peaks are thought to be caused by migration of space charge. A simulation calculation is made