Dielectric properties of strontium titanate synthesized by means of solid state reactions activated mechanically

In this work, strontium titanate samples were prepared starting from SrCO3 and TiO2 powders mixture. Raw materials were activated mechanically in a planetary mill and then calcined at different temperatures (900 to 1300 degrees C). Powders after grinding were analyzed by differential thermal analysis in order to follow the carbonate decomposition. On the other hand, samples resulting from heat treatment were characterized by XRD, SEM and electrical measurements. XRD analysis determines that SrTiO3 synthetized presents the cubic structure of perovskite. Complete reaction for SrTiO3 compound formation occurs at 1200 degrees C. SEM observations indicate the presence of a microstructure with very small gran size and consequently a large number of grain boundaries. Electrical measurements suggest the formation of a material with high insulating capacity. With this evidence, it can be concluded that solid state reactions activated mechanically, proved to be an effective way to fabricate strontium titanate compound with very fine microstructure and high insulating behavior.