The role of TiO2 powder on the SrTiO3-based synthesized varistor materials

The role of two kinds of near spec-pure TiO2 powder from two sources, designated as high pure and low pure, on SrTiO3-based varistor materials is investigated. Each of these TiO2 powder sources is used in synthesizing SrTiO3 powder and then SrTiO3-based varistor samples are prepared. It is observed that more pure TiO2 reduces dissociative SrO content significantly by about 90% compared to the less pure TiO2. Further it is realized that the high pure TiO2 is conducive in achieving low grain resistivity having uniform distribution in the microstructure for the sintered device in the reducing atmosphere. Based on the results obtained in this study it is preferred to use the high pure TiO2 for making SrTiO3-based varistor materials. The sensitivity and performance of these varistor materials are attributed to the more pure TiO2.