Heat treatment effects on Fe3O4 nanoparticles structure and magnetic properties prepared by carbothermal reduction

Fe3O4 nanoparticles were prepared by carbothermal reduction method using glucose as carbon source. Heating temperature and holding time effects on crystalline phase composition and magnetic properties of Fe3O4 nanoparticles were investigated by X-ray diffraction, field-emission scanning electron microscopy and vibrating sample magnetometer. Pure Fe3O4 nanoparticles with an average crystallite size of 48 nm was obtained at higher heating temperature of 650 degrees C and shorter holding time of 0.5 h, or at lower heating temperature of 450 degrees C and longer holding time of more than 6 h. The crystallite size of Fe3O4 nanoparticles increases with heating temperature and holding time. Fe3O4 nanoparticles heated at 650 degrees C for 2 h have the highest saturation magnetization (M-s = 97.99 emu g(-1)), higher than Fe3O4 prepared by other techniques due to better microstructure, crystallinity and expanded crystalline cell. (C) 2010 Elsevier B.V. All rights reserved.