Microwave-hydrothermal synthesis and characterization of barium titanate powders

The synthesis of barium titanate (BaTiO₃) has been investigated under microwave-hydrothermal (M-H) conditions in the temperature range of 60-160°C using BaCl₂, and TiCl₄ as Ba, and Ti sources, respectively. The crystallized products were characterized by powder X-ray diffraction (XRD), scaning electron microscopy (SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and particle-size analysis techniques. The results showed the crystallization of BaTiO₃ phase at all the synthesis temperatures along with the formation of BaCO₃ as a minor impurity. The crystallization of BaTiO₃ powder having an average crystallite size of 0.3 μm with CO₃^2- content of 0.8% was achieved at 160°C in the presence of 10 M NaOH in 3 h. These results show that the M-H synthesis route is rapid, cost effective, and could serve as an alternative to obtain BaTiO₃ powders with submicron particle size.