Synthesis of granular Fe-Al203 by the sol-gel method

Abstract

We have investigated the structural and magnetic properties of a granular composite of iron particles dispersed in alumina matrix, obtained starting from an aqueous solution containing AI(NO3)3, 9H20 and FeSO4, 7H20. The samples were characterized by X-ray diffraction and fluorescence, Moessbauer spectroscopy (MS) and vibrating sample magnetometry (VSM). Samples with 7.8 wt per centum Fe were submitted to two different heat treatments with the aim of reducing the iron oxides into metallic iron. Series A was submitted to calcination between 100-C and 1200ºC, followed by reduction in ultra pure H2 at 600C during 2 h; Series B was submitted to reduction at 600C or at 1000ºC directly after drying at 80ºC. The applied synthesis method seems to be an interesting alternative way to obtain magnetic Fe nanoparticles in a non-magnetic alumina matrix.