| Title |
Research Paper - Electronic · Magentic & Optical Natorials - : A Study on the Fabrication and Magnetic Properties of Oxidation Resisting Silica - Coated Iron Particles |
| Authors |
강신우(Shin Woo Kang); 김영삼(Young Sam Kim) |
| Abstract |
Oxidation resistant ultra fine iron powder has been prepared by silica coating and reduction of magnetite powder. A uniform coating of silica on the surface of ultra fine (75 A˚) magnetite powder was possible in a water-glass solution at pH 10-11. The silica-coated magnetite powder was reduced in H₂ at 500-650℃. The size of reduced iron powder decreased as the reduction temperature decreased ; the mean size of the particles could be reduced down to 110 A˚. When the treatment was done at 550℃ for 5 hrs, the silica-coated iron particles with SiO₂/Fe=3.7 wt% showed the good oxidation resistance under 150℃ and magnetization value of 139.6 emu/g (at the magnetic field 10 kOe). |