The Influence of the Synthesis Method on the Characteristics of BaTiO₃

In this work, barium titanate powders were produced by sol-gel and sol-precipitation methods from metal alkoxides. In the sol-gel method, tetraisopropyl orthotitanate was mixed with 2-propanol, acetic acid and barium acetate, and the gel samples obtained were calcined at 600 °C, 800 °C and 1000 °C. Through the sol-precipitation method, tetraisopropyl orthotitanate was mixed with acetic acid and deionized water and precipitated by the addition of a concentrated solution of KOH. The products were calcined at various temperatures, and the microstructural and dielectric properties of the BaTiO₃ prepared for the two processes were analyzed and compared. The results of these analyses allowed us to observe an increase in the tetragonal phase and the dielectric constant (15-50 at 20 kHz) with increasing temperatures in the samples produced by the sol-gel method, while the sample obtained by sol precipitation was cubic. The presence of BaCO₃ is more evident in the sample produced by sol-precipitation, and the band gap of the products obtained did not show significant variation, changing the synthesis method (3.363-3.594 eV).