Unipolar characteristics of ZnO ceramics

The paper presents research on unipolar characteristics of ZnO ceramics. Dielectric response analysis is generally known method to characterize electrical properties of materials. It becomes important method for non-destructive testing. Recently, the possibilities and limitations of this method to reflect the deterioration processes due to thermal and electrical stress were investigated. The method is based on measuring the conduction and dielectric or polarization response. Present investigations are bringing extension to this research by high-energy pulse loading of samples that are used e.g. in production of gapless overvoltage protections. Moreover, the variations of characteristics due to pulse energy stress of samples are investigated.