Chiang Mai Journal of Science

A sol-gel method for the preparation of barium titanate was performed by the chemical polymerization between water-soluble barium acetate and titanium alkoxide in dried isopropanol, i.e. titanium (IV) ethoxide, titanium (IV) isopropoxide, titanium (IV) propoxide and titanium (IV) n- butoxide with a 1:1 mole ratio of Ba²⁺/Ti⁴⁺ in acidic conditions led to the formation of barium titanate gels. After suitable drying and calcination treatments of the gels at 700° C for 24 hr, four samples of crystalline barium titanate powders were obtained. The thermal decomposition of the barium titanate gels was followed by thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The XRD patterns of the barium titanate powders at a temperature of 700° C showed 6 peaks which matched with the standard barium titanate of JCPDS. Particle size characteristic of the calcined powders was investigated by TEM and Malvern Mastersizer. The purities of the barium titanate powders were analysed to yield high purity barium titanate powders in the range of 98-99%. The quantities of barium and titanium were also determined by the XRF and NAA techniques. Trace impurities were analysed by atomic absorption spectrophotometry. The results from gravimetric analysis indicate that stoichiometric (Ba:Ti » 1:1), high purity BaTiO₃ powders were obtained.