Final sintering stage of Ni-Zn ferrites and the influence of additives on structural and magnetic properties were studied. Ni-Zn ferrite with the nominal composition Ni 0.64 Zn 0.36 Fe 2 O 4 produced with conventional powder process. Sintering of ferrites at different temperatures has done. Grain growth and densification of samples measured after sintering. The results showed that temperature and time of heating have a great influence on grain growth, densification and magnetic parameters. A mathematical model has been developed based on Kinney’s model in 1976. The final equation of this model relates relative density,, to time, t, and temperature, T, by where is the final relative density and A is a constant depends on the temperature and sintering conditions. This simple model evaluated in the sintering of Ni-Zn ferrites. This work also focuses on the effect of low melting point additives such as PbO, V 2 O 5 , B 2 O 3 and Bi 2 O 3 magnetic properties and microstructural development of Ni-Zn soft ferrite. The ferrite was doped with these additives, range from 0 to 3.2wt% in steps of 0.4wt%. Results obtained revealed that that with increasing the amount of This kind of additives up to a certain percentage (for example 2.4 wt% for PbO), relative density and grain size increase and then decrease. Both the magnetic permeability and Curie temperature increased first and then decreased
