Synthesis and Characterization of CoFe2O4 Hollow Spheres

CoFe2O4 hollow spheres with sizes ranging from 600 nm to 1 μm were prepared through hydrothermal treatment of an aqueous solution containing glucose, ammonium iron(II) sulfate hexahydrate [(NH4)2Fe(SO4)2·6H2O], and cobalt(II) sulfate heptahydrate [CoSO4·7H2O], followed by calcination. The wall of the CoFe2O4 hollow spheres is composed of CoFe2O4 spinel nanoparticles with a size of ca. 30 nm and wall thickness of ca. 150 nm. Magnetic characterization indicates high coercivity and low saturation magnetization, which indicate potential applications as high‐density magnetic recording materials and drug carriers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) CoFe2O4 hollow spheres with sizes ranging from 600 nm to 1 μm were prepared through hydrothermal carbonization, followed by calcination. XRD, TEM, HRTEM, SEM, N2 adsorption–desorption, XPS, IR, and TG techniques were used to characterize the product in detail, and the magnetic properties were also investigated.