Investigation of electronic processes at the grain boundaries of a multilayer varistor

摘要

Dielectric properties and capacitance-voltage characteristics of the ZnO multilayer varistors were investigated. Three dielectric absorptions were observed in the frequency range from 10~4 to 10~6 Hz. These absorptions are considered to be due to the electron trapping at the grain boundary, Thermally electronic polarization and a migration loss. The C-V curves have a slight decrease, Followed by an increase and sharp decrease to a negative capacitance.