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Journal of the Korean Ceramic Society 1985;22(6): 21. |
실리카 피착이 철립말의 입자형태 및 자기특성에 미치는 영향 (제1보) |
오재희, 김종식, 류병환 |
인하대학교 공과대학 무기재료공학과 |
Effect of Silica Coating on Particle Shape and Magnetic Properties of Iron Powder(I) |
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ABSTRACT |
The properties of magnetic recording materials largely depend on their shape magnetic anisotropy. The control of their shape and size distribution is very important for improving magnetic properties. The silica-coated goethite$(SiO_2$/$alpha$-FeOOH=1.5wt%) having acicular shape was prepared. The sillica-coated goethite was heat-treated at 40$0^{circ}C$~1,00$0^{circ}C$ 1hr and then reduced at 50$0^{circ}C$ 2hr. When the silica-coated goethite was heat-treated at 80$0^{circ}C$ its acicular shape was maintained and its magnetic properties were improved(Hc: 1,325 Oe $sigma$m:138.8 emu/g, Rs:0.56) However the acicular shape of the paricles was broken for non-coated hematite obtained by dehydration at 80$0^{circ}C$ They were sintered and showed poor magnetic properties. |
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