Template-free synthesis of hollow α-Fe2O3 microspheres

Nearly monodisperse hollow alpha-Fe2O3 microspheres composed of nanoparticles have been successfully synthesized through a facile template-free hydrothermal method. The products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It is shown that the hollow alpha-Fe2O3 microspheres consist of well-aligned alpha-Fe2O3 nanoparticles with a mean diameter of about 15 nm. This facile reaction route presents an efficient method for mass production of monodisperse hollow magnetic nanomaterials. The final alpha-Fe2O3 microspheres exhibit special magnetic properties with a small remnant magnetization of 0.09 emu g(-1) and a high coercivity of 1121.67 Oe at room temperature.