Influence du silicium sur les proprietes magnetiques de lʹhematite effect of silicon on the magnetic properties of hematite

Manufacturing of soft ferrites with perfectly defined electronic and magnetic properties requires hematite of high purity, particularly without silicon. Consequently, we have studied the effects of different routes for doping haematite (α-Fe2O3) with silicon. We show that there is no reaction between silicon oxide and iron (III) oxide prepared by the ceramic way. On the other hand, by fayalite (Fe2SiO4) oxidation at 1000 °C, we can make silicon doped hematite. This doping, which does not exceed 0.4%, does not perturb the crystalline parameters but involves some modifications in the magnetic structure which are studied by magnetism and Mössbauer spectroscopy of 57Fe.