Hydrothermal precipitation and characterization of nanocrystalline BaTiO3 particles

• Published in: Journal of materials science Vol. 36; no. 20; pp. 4875 - 4882
• Main Authors: CIFTCI, E, RAHAMAN, M. N, SHUMSKY, M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.10.2001; Springer Nature B.V
• Subjects: Atomic beam spectroscopy; Barium hydroxide; Barium titanates; Chemistry; Colloidal state and disperse state; Crystal defects; Crystal structure; Emission analysis; Exact sciences and technology; General and physical chemistry; Materials science; Particle size; Particle size distribution; Powders; Reaction time; Thermal analysis; Titanium dioxide; Transmission electron microscopy; Weight loss; Ternary compound; Scanning electron microscopy; Precipitation; Barium Oxides; Transmission electron microscopy; Transition metal Compounds; Barium Titanates; X ray diffraction; Alkaline earth metal Compounds; Hydrothermal condition; Nanocrystal; Titanium Oxides
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1011828018247

Crystalline BaTiO3 powders were precipitated by reacting fine TiO2 particles with a strongly alkaline solution of Ba(OH)2 under hydrothermal conditions at 80°C to 240°C. The characteristics of the powders were investigated by X-ray diffraction, transmission electron microscopy, thermal analysis and atomic emission spectroscopy. For a fixed reaction time of 24 hours, the average particle size of BaTiO3 increased from ∼50 nm at 90°C to ∼100 nm at 240°C. At synthesis temperatures below ∼150°C, the BaTiO3 particles had a narrow size distribution and were predominantly cubic in structure. Higher synthesis temperatures produced a mixture of the cubic and tetragonal phases in which the concentration of the tetragonal phase increased with increasing temperature. A bimodal distribution of sizes developed for long reaction times (96 h) at the highest synthesis temperature (240°C). Thermal analysis revealed little weight loss on heating the powders to temperatures up to 700°C. The influence of particle size and processing-related hydroxyl defects on the crystal structure of the BaTiO3 powder is discussed.