Temperature Dependent Electrical Characteristic of ZnO Microvaristor Powder

Abstract:
The characterisation of ZnO microvaristor powder and ZnO microvaristor filled compounds requires the investigation of their intrinsic material properties. The electrical properties of doped ZnO ceramics depend on electric field strength and temperature and therefore these parameters have to be controlled during measurement. The paper presents an arrangement to measure the voltage-current (U-I-) or field strength-current density (E-j-) characteristic with homogeneous electric field and current distribution inside the specimen and the possibility to temper the test electrodes. Further, a method is described how to define the characteristic values of current-voltage curves, i.e. the varistor voltage and the leakage current or their specific values, respectively. Finally, first results of the non-linear U-I- or E-j-curve using the measuring arrangement are given.