Abstract
The preparation of highly porous MnFe 2O 4-SiO 2 and NiFe 2O 4-SiO 2 nanocomposite aerogels with high purity and homogeneity was successfully achieved by a sol-gel procedure involving urea- assisted co-gelation of the precursor phases firstly applied for the synthesis of CoFe 2O 4-SiO 2. This method allows fast gelation, giving rise to aerogels with 97% porosity. The structural, morphological and textural characterization as a function of thermal treatments was carried out by a multitechnique approach confirming that, as in the case of CoFe 2O 4-SiO 2, the formation of single nanocrystals of manganese ferrite and nickel ferrite with spinel structure occurs after heating at 750 °C and is complete at 900 °C when the high porosity typical of aerogels is still retained. Thermogravimetric analysis (TG), differential thermal analysis (DTA), N 2-physisorption at 77 K, powder X-ray diffraction (XRD), and transmission electron microscopy (TEM) indicate that the compositional homogeneity, crystallite size, thermal stability, and porosity are controlled by the sol-gel parameters of the preparation.
Original language | English (US) |
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Pages (from-to) | 1008-1016 |
Number of pages | 9 |
Journal | Journal of nanoscience and nanotechnology |
Volume | 10 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2010 |
Externally published | Yes |
Keywords
- Aerogel
- Ferrite
- Nanocomposite
- Nanoparticles
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics
- Bioengineering
- Biomedical Engineering
- General Materials Science