STRUCTURAL, ELECTRICAL AND MAGNETIC PROPERTIES OF NANOPARTICLE SIZE ALUMINUM SUBSTITUTED COBALT FERRITE

Nano-crystalline Aluminum substituted cobalt ferrite samples CoFe2-2yAl2yO4 (where y = 0.0, 0.05, 0.15 & 0.25) have been prepared by standard ceramic technique. The effect of Al3+substitution in cobalt ferrites with respect to their structural, electrical and magnetic properties has been investigated in this paper. The types of phase formed of produced samples are investigated using X-ray diffraction. Using XRD data, the lattice parameters were calculated for all samples. The substitution of Al effects in decreasing the lattice constant. The decrease in lattice constant is attributed to difference in ionic radii of Fe3+ and Al3+ ions. The effects of Al3+on both AC and DC Electrical properties are studied. DC Electrical resistivity is found to increase with increase of aluminum content. Activation energies in ferromagnetic region are found very less than that of paramagnetic region. Electrical properties of synthesized nanoparticles are studied by AC conductivity measurement. The dielectric constant ε’, complex permittivity ε” and dielectric loss tangent (tanδ) measured at room temperature as a function of the frequency. The effect of Al3+ ion substitution of cobalt ferrite on the AC electrical resistivity and dielectric properties in frequency range 20 Hz to 1MHz. were studied.