A Novel Type of Magnetic Fe₂O₃/Fe₃O₄ Heterogeneous Microparticles Prepared via the Ethanol-Water Reflux and Rapid Combustion Process

A novel type of magnetic Fe₂O₃/Fe₃O₄ heterogeneous microparticles with ellipsoidal macropores was prepared via the ethanol-water reflux and rapid combustion process. The experimental results showed that the volume of absolute ethyl alcohol and the calcination temperature were the key factors to the grain sizes and the magnetic properties, the calcination temperature largely affected the saturation magnetization and the grain size of Fe₂O₃/Fe₃O₄ heterogeneous microparticles, and the amount of absolute ethyl alcohol also tremendously affected the saturation magnetization, however, the amount of absolute ethyl alcohol affected little on the grain size. Fe₂O₃/Fe₃O₄ heterogeneous microparticles calcined at 200 °C for 1 h with absolute ethyl alcohol of 20 mL had the largest saturation magnetization of 90.1 Am²/kg.