Sol–gel synthesis and characterization of BaTi2O5 powders

BaTi₂O₅ powders were synthesized using a sol–gel method and characterized. Phase evolution and characteristics of the samples were studied using differential scanning calorimetry, thermogravimetric analysis and X-ray diffractometry. The results show that the formation of BaTi₂O₅ starts around 800 °C and continues until 1200 °C in air, and in this calcination temperature range all powders appear to be single-phase monoclinic BaTi₂O₅. The mechanism of BaTi₂O₅ formation was studied by Fourier-transform infrared spectroscopy. The infrared absorption peaks confirm the existence of a substitution reaction with the chelating reagent corresponding to different modes of vibration characteristic of the acetate group. Scanning electron microscopy observations reveal that the size of the particles that are nearly round in shape formed due to agglomeration is about 0.1–1.5 μm and increases with calcination temperature. PACS 81.70.Pg; 81.20.Fw; 77.84.Dy; 61.10.Nz; 33.20.Ea