| 수열합성법에 의한 BaTiO3분말합성 및 소결체의 제조 |
| 이병우, 최경식, 신동우1 |
한국해양대학교 기계소재공학부
1경상대학교 세라믹공학과 |
| Preparation and Characterization of Hydrothermal BaTiO3 Powders and Ceramics |
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| ABSTRACT |
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BaTiO$_3$ fine powders were synthesized by hydrothermal process from peroxo-coprecipitate precursors. The peroxo-coprecipitates were obtained by addition of the BaCl$_2$, TiCl$_4$, and $H_2O$$_2$ aqueous solution to an ammonium solution. Hydrothermal reaction was conducted at various reaction temperatures, times and pH ranges. Unlike the conventional hydrothermal synthesis which needs highly alkaline condition over pH 13 with KOH or NaOH, the present method offered well-developed crystalline (perovskite) BaTiO$_3$ powders synthesized below pH 12 with use of ammonium solution. It was found that the phase-pure fine powders were formed at temperatures as low as 11$0^{circ}C$ and the properties of the powders synthesized over 13$0^{circ}C$ were almost same regardless of the reaction time. BET surface area of the prepared powder was as high as 76 $m^2$/g and the calculated particle (particulate) size was below 20 nm. The ultrafine particulates formed weak agglomerates. The microstructure and dielectric properties of BaTiO$_3$ ceramics sintered at the temperature range of 1150~125$0^{circ}C$ were evaluated. |
| Key words:
Hydrothermal process, $BaTiO_3$, Powder synthesis, Coprecipitates |
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