Mossbauer study of magnetite nanowire in MCM-41 type mesoporous silica templates

Arrays of Fe3O4 nanowires embedded in mesoporous ordered silica were obtained in two ways: dissolving Fe3+ ions in an aqueous medium and their adsorption on internal and external surfaces, with the use of a Fe-EDTA complex. Magnetite polycrystalline nanowires were characterized by means of X-ray diffraction and Fe-57 Mossbauer spectroscopy (MS). The average length of these nanowires is about 70 nm and their diameter is about 3 nm. Mossbauer studies evidenced that the composites consist of very small Fe3O4 particles. Almost 80% of particles exist in a paramagnetic state.