BaTiO3가스센서 감지물의 제조와 특성 연구 |
서동진, 장경욱, 임실묵1, 김좌연2, 최병현3, 박경순 |
세종대학교 신소재공학과 ㆍ 신소재연구소 1한국산업기술대학교 신소재공학과 2호서대학교 신소재공학과 3요업기술원 신기능재료연구부 |
Fabrication and Characteristics of Sensing Materials for BaTiO3 Gas Sensors |
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ABSTRACT |
The porous sensing materials for BaTiO$_3$ gas sensors were fabricated by adding the graphite powders. The crystalline structure and microstructure of the porous BaTiO$_3$-based ceramics were studied. All the sintered bodies showed a tetragonal perovskite structure. The porosity increased with increasing graphite contents. This is mainly due to an enhanced evolution of CO and $CO_2$ gases resulting from the exothermic reactions of graphite and oxygen during the sintering. It was found that the discrepancy in the resistivities measured in air and CO atmospheres at high temperatures (>∼20$0^{circ}C$) became remarkable with increasing temperature. The sensitivity of CO gas increased with porosity, since the reactions between CO gas and $O_2$$^{[-10]}$ and between CO gas and $O^{[-10]}$ are active due to the formation of many reaction sites. The porous BaTiO$_3$-based ceramics could be promising as a sensing material for CO gas sensors. |
Key words:
$BaTiO_3$, Graphite, Porosity, Microstructure, Electrical resistivity |
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