Synthesis and magnetic properties of iron oxide–silica aerogel nanocomposites

Iron oxide–silica nanocomposite aerogels were produced by sol–gel procedure followed by the hypercritical evaporation of the solvent. Aerogels hosting maghemite were synthesized from the precursors TEOS and TMOS. Mean oxide particle size seems to be strongly influenced by the solvent. The magnetic properties of the iron oxide particles hosted in silica aerogeles pores were studied by means of magnetometry and AC susceptometry. Interrelation between synthesis parameters, structure and magnetic behavior is discussed.