Abstract
Supercritical water can provide an unique reaction atmosphere for synthesizing metal oxide nanoparticles. Due to the drastic change of properties of water around the critical point, including density, dielectric constant and ionic product, the reaction phase with O2 or H2 gas and the reaction rate and equilibrium can be varied to synthesize new materials or define particle morphologies. In this work, hydrothermal crystallization experiments are performed with several types of flow apparatus that allow convenient manipulation of variables such as temperature, pressure, and residence time. Key features in the flow modes and material preparation are discussed. The proposed supercritical hydrothermal synthesis method has the following desirable features: i) nanoparticles can be produced, ii) morphology of the produced particles can be controlled with small changes in pressure or temperature, and iii) a reducing or oxidizing atmosphere can be applied by introducing oxygen or hydrogen or other glass. An overview of this method is given for functional material synthesis of significant industrial interest including barium hexaferrite magnetic particles, YAG/Tb phosphor fine particles and lithium cobalt fine crystals.
Original language | English |
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Title of host publication | Proceedings of the Second International Conference on Processing Materials for Properties |
Editors | B. Mishra, C, Yamauchi, B. Mishra, C. Yamauchi |
Pages | 459-462 |
Number of pages | 4 |
Publication status | Published - 2000 Dec 1 |
Event | Proceedings of the Second International Conference on Processing Materials for Properties - San Francisco, CA, United States Duration: 2000 Nov 5 → 2000 Nov 8 |
Other
Other | Proceedings of the Second International Conference on Processing Materials for Properties |
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Country | United States |
City | San Francisco, CA |
Period | 00/11/5 → 00/11/8 |
Keywords
- Bariumhexaferrite
- Hydrothermal synthesis
- LiCoO
- Phosfer
- Supercritical water
ASJC Scopus subject areas
- Engineering(all)