Heat treatment effects on Fe 3O 4 nanoparticles structure and magnetic properties prepared by carbothermal reduction

Abstract

Fe 3O 4 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 Fe 3O 4 nanoparticles were investigated by X-ray diffraction, field-emission scanning electron microscopy and vibrating sample magnetometer. Pure Fe 3O 4 nanoparticles with an average crystallite size of 48 nm was obtained at higher heating temperature of 650 °C and shorter holding time of 0.5 h, or at lower heating temperature of 450 °C and longer holding time of more than 6 h. The crystallite size of Fe 3O 4 nanoparticles increases with heating temperature and holding time. Fe 3O 4 nanoparticles heated at 650 °C for 2 h have the highest saturation magnetization ( M s = 97.99 emu g −1), higher than Fe 3O 4 prepared by other techniques due to better microstructure, crystallinity and expanded crystalline cell.