Solid state synthesis of Mg–Ni ferrite and characterization by XRD and XPS

Single-phase magnesium–nickel ferrites with varying amounts of nickel and magnesium were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. A plot of lattice parameter versus composition of the ferrites (MgxNi(1−x)Fe2O4, x⩽1) showed an abrupt deviation of lattice parameter linearity near MgFeO4. The deviation was explained in terms of the distribution of Mg2+ in the octahedral and tetrahedral sites of the oxygen lattice. In XPS spectra, a broadening of the Mg 1s peak in Ni rich Mg–Ni ferrites from that observed in pure MgFe2O4, was explained by changes in the distribution of Mg2+ ion in tetrahedral and octahedral sites. A depth distribution of Mg in Ni0.5Mg0.5Fe2O4 showed an enrichment of Mg on surface.