Structure and Magnetic Properties of Nanocrystalline Spinel Ferrites Obtained by High Energy Ball Milling

Abstract

The mechanochemical synthesis of zinc, manganese and zinc-manganese nanocrystalline ferrites obtained by mechanical milling from precursors: a) oxides and carbonates, b) ceramic products and c) hydroxides and oxides is presented. Final products have been characterised by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Mossbauer spectroscopy and vibrating sample magnetometry (VSM). Results are compared with the ferrites synthesised by the ceramic method. Depending on the Mn/Zn ratio. mechanical treatment leads to ferrites having nanocrystalline structure with improved or decreased magnetic properties compared to ceramic ones. Subsequent thermal treatment of the disordered mechano-synthesized ferrites leads to its crystallisation at temperatures which are lower than those at which the crystalline ferrites are formed by the ceramic method.