The structure and the magnetic properties of a series of Fe 2 O 3 -SiO 2 nanocomposites (16.9 and 28.5 wt% of Fe 2 O 3 /(Fe 2 O 3 + SiO 2 )), prepared by a sol-gel method and submitted to thermal treatments in a temperature range 300-700°C, were investigated through X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy and magnetometry. Poorly crystallized particles, belonging to the 2-line ferrihydrite phase, were found in all the samples and recognized as precursors of the γ-Fe 2 O 3 that form in Fe 2 O 3 -SiO 2 nanocomposites at T > 700°C. The result was achieved through a detailed comparison of structural and magnetic properties of nanocomposites with a bulk iron (III) oxide hydrated reference sample.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry