Characteristics of BaTiO{sub 3} particles prepared by spray-coprecipitation method using titanium acylate-based precursors
- Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Div. of Chemical Engineering
- Sogang Univ., Seoul (Korea, Republic of). Dept. of Chemical Engineering
BaTiO{sub 3} particles of ultrafine size and high crystallinity were produced by a spray-coprecipitation technique. To improve stability, titanium isopropoxide was acylated using acetic acid. The sol solutions were prepared by mixing the titanium acylate with aqueous barium acetate. Spray-precipitation was performed in concentrated KOH solution (pH > 13). Investigated variables were the metal content and Ba/Ti ratio in sol solutions, the reaction temperature and time, and the calcination temperature. BaTiO{sub 3} particles were synthesized in an aggregate form composed of tiny spherical, crystalline grains (20--30 nm in diameter). The barium-deficient stoichiometry of resulting particles was closely related to a rather poor precipitation yield of barium ions in KOH solution. Crystalline BaTiO{sub 3} phase was formed by two different mechanisms: ion-solid reaction and solid-state reaction. BaTiO{sub 3} particles, in purely cubic phase as synthesized, underwent a phase transition to tetragonal phase by calcination over 500 C.
- OSTI ID:
- 328243
- Journal Information:
- Chemistry of Materials, Vol. 10, Issue 12; Other Information: PBD: Dec 1998
- Country of Publication:
- United States
- Language:
- English
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