Combustion synthesis and characterization of NiCuZn ferrite powders

In this paper, the feasibility of synthesizing NiCuZn ferrite powders by combustion synthesis (CS) reaction is demonstrated through igniting the mixtures of iron, iron oxide, copper oxide, zinc oxide and copper carbonate under different oxygen pressure values. The ferrite powders produced directly from the CS reaction and after annealing at 800 °C for 2 h are characterized by XRD, SEM, XPS and VSM. The results show that the spinel phase in the combustion products increases with the decrease of the diluent content and the increase of the oxygen pressure. Heating the as-synthesized ferrite at 800 °C for 2 h affords pure crystalline NiCuZn ferrite, which possesses better magnetic properties. XPS studies confirm that copper ions in the as-synthesized ferrite are present in the different ionic states of the A- and B-sites, while copper ion is divalent in the B-sites only for the annealed products.