Characterization of Synthesized SrTiO3 from Purified Celestite Concentrate Using Mechanochemical Process

Strontium titanate (SrTiO3) was synthesized by mechanochemical processing of a mixture of purified celestite concentrate and titanium dioxide. First, SrCO3 was prepared from a mixture of purified celestite concentrate and sodium carbonate via a mechanochemical method, then SrTiO3 synthesizes from a stoichiometric mixture of SrCO3 and TiO2 powder. After isothermal heating of a 5-h milled mixture of SrCO3-TiO2 powder at 900 ℃ for 2 h, a single phase of SrTiO3 with a cubic structure was produced. The synthesized SrTiO3 powders were sintered at different temperatures for 2 h. The produced SrTiO3 samples were characterized using SEM micrographs, and the phase changes were evaluated using XRD analyses. The changes in the density and dielectric constant of the sintered samples were also determined. The results showed that the properties of SrTiO3 highly depended on the sintering temperature. Owing to the microstructure and grain size of the produced SrTiO3 in the milled samples, the dielectric constant of the milled sample was lower than that of the un-milled sample.