Oxidation behaver of Fe3O4 coaded with SiO2 by fluidized CVD

Fe3O4 magnetic powder coated with uniform SiO2 layer was obtained by fluidized CVD technique. The oxidation mechanism and the kinetics of the SiO2 coated Fe3O4 were investigated. The results show that the mechanism of oxidation of the SiO2 coated Fe3O4 is inferred as phase boundary reaction, spherical symmetry. The activation energy is increased with increasing silica content. The silica protect layer on the Fe3O4 magnetic powder formed by fluidized CVD technique can improve the oxidation-resistance of Fe3O4.