The Influence of Sintering Parameters and Subsequent Thermal Treatment on U-I Characteristics and Degradation of ZnO Varistors

Abstract

The fabrication of varistor ceramics, characterized by stable electrical properties, was considered on the basis of sintering parameters and subsequent thermal treatment. The process of accelerated degradation of electrical characteristics in severe conditions was analysed. The measured K–J curves were used for the determination of electric parameters. The comparative analysis of these results and electronic paramagnetic resonance data1 was the basis of the conclusions concerning the formation of potential barrier, its improvement and subsequent degradation at the grain boundary.