Synthesis and characterization of ultrafine spinel ferrite obtained by precursor combustion technique

摘要

Nanoparticles of the spinel ferrite, Co_0.6Ni_0.4 Fe_2O_4 have been synthesized by the precursor combustion technique. This synthetic route makes use of a novel precursor viz. metal fumarato hydrazinate which decomposes autocatalytically after ignition to yield nanosized spinel ferrite. The X-ray powder diffraction of the "as prepared" oxide confirms the formation of monophasic nanocrystalline cobalt nickel ferrite. The thermal decomposition of the precursor has been studied by isothermal, thermogravimetric and differential thermal analysis. The precursor has also been characterized by FTIR, and chemical analysis and its chemical composition has been fixed as Co_0.6 Ni_0.4Fe_2(C_4H_2O_4)_3·6N_2H_4. The Curie temperature of the"as prepared" oxide was determined by ac susceptibility measurements.