Morphological forms of {alpha}-alumina particles synthesized in 1,4-butanediol solution
- Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering
Phase-pure, monodispersed, hexagonal plates of single-crystal {alpha}-alumina ({approx} 2 {micro}m wide and {approx} 0.5 {micro}m thick) have been prepared via precipitation by treating an aluminum hydrous oxide precursor in 1,4-butanediol at 300 C under autogenous vapor pressure. Present work shows that KOH is the only reagent that precipitates an aluminum hydrous oxide precursor suitable to synthesize {alpha}-alumina in 1,4-butanediol solution. In contrast, the use of NaOH or NH{sub 4}OH as the precipitating reagent for the precursor material does not yield the alpha phase. The solution pH at which the precursor materials are precipitated is also a critical factor for the formation of {alpha}-Al{sub 2}O{sub 3}. Phase-pure {alpha}-alumina powders were also only synthesized from the aluminum hydrous oxide precursors precipitated in the pH range from 10 to 10.5. The results of X-ray diffraction and scanning electron microscopy indicate that longer reaction times promote the phase transformation from the intermediate boehmite phase to {alpha}-alumina. The complete transformation from boehmite to {alpha}-alumina requires reaction times of about 12 h.
- OSTI ID:
- 203542
- Journal Information:
- Journal of the American Ceramic Society, Vol. 79, Issue 1; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
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