Investigation of heat treatment condition, ethylene glycol and deionized   water effects on the phase structure of Ba0.6Sr0.4TiO3 nanoparticles produced   by the sol-gel method
  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. 
Mohammadali Ajam, Abolghasem Nourmohammadi, S. Mohammad Hasan Feiz
cond-mat.mtrl-sci