  Ba0.6Sr0.4TiO3 nanoparticles were synthesized by the sol-gel method. The
effects of the heat treatment conditions, ethylene glycol (EG) and deionized
water (DW) on their phase structure and formation of the undesirable barium
carbonate (BaCO3) phase were investigated. It was found that increasing the
temperature of the samples caused an increase in the peak intensities of
perovskite structures, and a decrease in the intensities of the BaCO3 peaks.
Moreover, omitting EG, the sol stabilizer, and water, the solvent, decreased
the peak intensities of BaCO3. Decreasing the heating rate caused better
burnout of the contained organic materials and, as a result reduced the peak
intensity of BaCO3. But, it was impossible to remove the BaCO3 completely up to
850C. However, single-phase perovskite barium strontium titanate nanoparticles
were obtained at 750C by using an acetic acid based precursor sol through
decreasing the gel heating rate, and omitting EG and DW.
