X-Ray diffraction and mo¨ ssbauer spectra of nickel ferrite prepared by combustion reaction

Nickel ferrite powders with a nominal NiFe2O4 composition were synthesized by combustion reaction using urea as fuel. The powder was obtained using a vitreous silica basin heated directly on a hot plate at 480 C until self-ignition occurred. After combustion, the powder was calcined at 700 C for 2 h. The formation of the spinel phase and the distribution of cations in the tetrahedral and octahedral sites of the crystal structure were investigated by the Rietveld method, using synchrotron X-ray diffraction data and Mo¨ ssbauer spectroscopy. The material presented a crystallite size of 120 nm and magnetic properties. The resulting stoichiometry after the Rietveld refinement was (Fe0.989(2) Ni0.011(2)) [Fe1.012(2) Ni0.989(2)] O4.