Electrical And Magnetic Properties Of Nickel Substituted Cadmium Ferrites

Abstract Nickel substituted cadmium ferrites with general formula Cd1-xNixFe2O4 where x 0.1 0.2 0.3 were prepared by solid state reaction method. The particle size of the ferrite samples were estimated from X-ray diffraction studies after the confirmation of the formation of single phase spinel structure of the ferrites. The two prominent IR absorption bands 269471 26 269472 of the samples observed in the regions 600 cm-1 and 400 cm-1 are assigned to vibrations of tetrahedral and octahedral complexes respectively and using these IR band frequencies the force constants for tetrahedral KA and octahedral KB sites were estimated. SEM images of the sample shows increase of the average grain diameter with the increase of nickel content in the cadmium ferrite. The purity and stoichiometry of the compositions after final sintering were confirmed by Energy Dispersive X-ray EDX analysis. DC resistivity measured as a function of temperature shows the break at Curie temperature indicating the transition from ferrimagnet to paramagnet region. The dielectric constant 26949 and loss tangent tan 26948 measured at room temperature as a function of frequency 40 Hz to 110 MHz as a function of temperature at certain frequencies 1KHz 10KHz 100KHz 1MHz 10MHz shows dielectric dispersion. Dielectric constant and loss tangent decreases with increase of frequency indicating decrease in polarization. Infact dielectric constant 26949 and loss tangent tan 26948 reaches a constant value for all the samples above certain higher frequency. The plot of dielectric constant with temperature shows two broad peaks one around 1800C and another around 380oC for frequencies in the range from 1KHz - 100KHz. Saturation magnetization and magnetic moments of the ferrite samples estimated from VSM analysis were found to increase with Nickel content.