Hydrothermal Precipitation and Characterization of Nanocrystalline BaTiO₃ Particles
Carter, C. B.
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.
E. Ciftci et al., "Hydrothermal Precipitation and Characterization of Nanocrystalline BaTiO₃ Particles," Journal of Materials Science, Springer Verlag, Jan 2001.
The definitive version is available at http://dx.doi.org/10.1023/A:1011828018247
Materials Science and Engineering
Keywords and Phrases
Polymer Sciences; Industrial Chemistry/Chemical Engineering; Characterization and Evaluation Materials; Mechanics
Article - Journal
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