Synthesis of Monodisperse Magnetite Nanocrystals via Partially Reduced Precipitation Method

摘要

Ferromagnetic Fe_3O_4 nanocrystals with sphere-like morphology have been successfully synthesized by a partial reduction-precipitated crystallization method using ferric chloride as single iron source, hydroxylammonium chloride (HONH_3C1) as reducing reagent, and ammonia as precipitating reagent. This synthesis is carried out in a reducing atmosphere in the absence of inert gas. The chemical composition and morphology of the sample were characterized by X-ray power diffraction (XRD), X-ray photoelectron spectra (XPS), and transmission electron microscopy (TEM). The experiment results clearly show that the synthesized sample mainly consists of a large quantity of spherical Fe_3O_4nanoparticles with a size of about 5-11 nm, and HONH_3C1 plays important roles in the formation of the products. Besides, the magnetic property of the sample has been investigated using a vibrating sample magnetometer (VSM) and the magnetization saturation value is approximately 43.5 emu/g.