Analysis of grain-boundary in SrCoO_3-doped ZnO varistors and its electrical characteristics

摘要

The grain-boundary and its electrical characteristics in SrCoO_3-doped ZnO varistors were studied. The grain-boundary around ZnO-grain is probably composed of SrCoO_3, and its electrical behavior is clearly different from two conventional types of Bi-and Pr-based ZnO varitors. The non-linearity and characteristic behavior could be explained by considering the n-p-n hetero-structure at the grain boundary. SrCoO_3 in the grain-boundary region should play crucial roles of not only the appearance of non-liner property but also the formation of different hetero-structure from double Schottky-barrier model on conventional varistors.