Thermally stimulated currents as a measure of degradation of zinc oxide varistors |
| |
Authors: | Witold Mielcarek Dorota Nowak-woźny Krystyna Prociów Adam Gubański |
| |
Institution: | 1. Institute of Electrotechnics , M.Sk?odowskiej-Curie 55/61, Wroc?aw , 50-369 , Poland;2. Technical University of Wroc?aw , Wybrze?e Wyspiańskiego 27, Wroc?aw , 50-372 , Poland |
| |
Abstract: | ZnO varistor degradation phenomena was studied using thermally stimulated current (TSC) method. It is believed that asymmetrical degradation of V-I characteristics caused by DC biasing is due to charge accumulation on the reverse biased side of ZnO grain barrier. The TSCs' measuring system and cryostat apparatus used in experiment were described. The thermally stimulated currents observed in this study for varistor samples doped with different amounts of Co, due to their recovery from asymmetrical electric stress, could not be controlled by movement of Zn interstitials with activation energy 0.55 v eV, as it is widely believed, for the TSC activation energy determined in this experiment was 0.39 v eV. |
| |
Keywords: | Zno Varistor Degradation Interstitials |
|
|