Facile ultrafast microwave synthesis of monodisperse MFe_2O_4 (M=Fe, Mn, Co, Ni) superparamagnetic nanocrystals

摘要

A series of metal ferrite nanocrystals MFe_2O_4 (M=Fe, Mn, Co, Ni) were prepared via a microwave synthesis strategy. The whole synthesis process could be accomplished in a few minutes at a moderate temperature and without inert gas protecting. The resulting products were systematically characterized and showed uniform spherical morphology with an average particle size of 6.0 nm, well crystallinity, superparamagnetic property and relatively high saturation magnetization. A microwave heating based classical crystallization mode was proposed for the formation of these nanocrystals. This work sheds new light on the synthesis of magnetic nanoparticles with improved properties through a rapid, "green" microwave-assisted synthesis strategy.