Influence of Nano-Particle on Grain Boundary Barrier Structure of TiO_2 Varistor Ceramics

Grain boundary barrier structure (GBBS) of nano-titania modified TiO2 varistors ceramics were investigated by an experimental method. Microstructures of TiO2 ceramics samples were tested through SEM. Based on the thermoelectronic emissionat theory, grain boundaries barrier structure (GBBS) of TiO2 samples were obtained by analyzing electrical properties of the samples. From room temperature to 320℃, the resistivityρof TiO2 varistors ceramics samples were measured. GBBS of samples were calculated resulting from the curves of lnσvs. 1/T. The influence of microstructures and barriers structures on the electrical properties of varistors ceramics was discussed. The results show that the nano-titania additive content x = 5mol% is reasonable.