Reduction behaviour of MgFe 2 O 4 with the synthesis of Fe/MgO nanocomposite

Abstract

Magnesioferrite (MgFe₂O₄) powder was prepared through the ceramic route by calcination of a stoichiometric mixture of magnesium oxide and iron oxide. The produced powders of MgFe₂O₄ were isothermally reduced in pure hydrogen at 800–1000°C. Based on thermogravimetric analysis, the reduction behaviour of magnesioferrite and the kinetics reaction mechanism were studied. The initial ferrite powder and the various reduction products were characterised by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) analysis to reveal the effect of hydrogen reduction on composition, microstructure and magnetic properties of produced samples. Completely homogenous nanocrystalline (77 nm) Fe/MgO composite was obtained by the reduction of MgFe₂O₄ powders. Depending on the kinetics obtained data from reduction process, the reduction rate was found to be controlled by interfacial chemical reaction mechanism. The magnetic characterisation of the formed Fe/MgO nanocomposite were enhanced under the effect of reaction temperature whereas the coercivity values decreased from 57·99 to 33·58 Oe while the saturation magnetisation increased from 110·7 to 148·1 emu g⁻¹.