Effect of Sintering Temperature on Apparent Density and Transport Properties of NiFe2O4: Synthesized from Nano Size Powder of NiO and Fe2O3

Polycrystalline NiFe2O4 was prepared by solid state reaction from nano size powders of NiO and Fe2O3 which were synthesized by wet chemical method. Enhancement of apparent density of the sample has been observed with the increase in sintering temperature and has great influence on the transport properties of NiFe2O4. Decrease in resistivity with increasing temperature confirms the semiconducting behavior of the prepared ferrites. Also it was found that the value of resistivity at room temperature decreased with the increase in sintering temperature. Variation of activation energy has been found for different sintering temperatures. Dielectric constant shows the normal behavior of the ferrite materials which can be explained on the basis of Koop’s two-layer model and Maxwell-Wagner polarization theory. Also the increased value of dielectric constant (?) has been observed with the increase in sintering temperature.