NANOCRYSTALLINE ALPHA-FE2O3 SOL-GEL THIN-FILMS - A MICROSTRUCTURAL STUDY

The structure of alpha-Fe2O3 sol-gel thin films, obtained from an alko xide precursor, was investigated by X-ray diffraction, X-ray absorptio n spectroscopy and conversion electron Mossbauer spectroscopy. Samples heated at 300 degrees C were amorphous, while those treated at 400 an d 500 degrees C showed the presence of crystalline hematite. The cryst allites were small enough to give rise to the superparamagnetic effect . In the nanostructured films, the alpha-Fe2O3 particles were not link ed together but dispersed in a network of amorphous ferric oxide.