Synthesis and Characterization of CoFe₂O₄ Hollow Spheres

Abstract

Abstract CoFe 2 O 4 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 [(NH 4 ) 2 Fe(SO 4 ) 2 · 6H 2 O], and cobalt(II) sulfate heptahydrate [CoSO 4 · 7H 2 O], followed by calcination. The wall of the CoFe 2 O 4 hollow spheres is composed of CoFe 2 O 4 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)