Structure and magnetic properties of ultrafine superparamagnetic Sn-doped magnetite nanoparticles synthesized by glycol assisted co-precipitation method

摘要

The usage of ethylene glycol as high boiling solvent results in the formation of ultrafine, highly crystalline tin doped magnetite nanoparticles with an average size equal to 4.85 nm. The oxidation of Sn2+ ions to Sn4+ ions under the formation of magnetite structure was observed. This process was related to the reduction of Fe3+ ions to the Fe2+ ions. Thereafter, Sn4+ ions can replace Fe3+ ions in the magnetite structure, which affects the magnetic properties. The synthesized Fe3O4:Sn4+ nanoparticles have superparamagnetic behavior, high saturation magnetization equal to 49.7 emu/g and very low coercivity equal to 13.29 Oe. The content of Sn4+ ions in synthesized nanoparticles was equal to 1.87 at.%