Impact Of Transition Metal Ion Doping On Electrical Properties Of Lithium Ferrite Nanomaterials Prepared By auto Combustion Method
1Department of Physics, Osmania University, Hyderabad 500007, Telangana, India
2Department of Physics, University College of Science, Sifabad, O.U, Hyd, Telangana, India
Adv. Mater. Lett., 2015, 6 (2), pp 179-185
Publication Date (Web): Feb 08, 2015
Copyright © IAAM-VBRI Press
Nano crystalline cobalt substituted lithium ferrites having chemical formula [Li 0.5Fe0.5]1-x Cox Fe2O4 (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been prepared by the citrate gel auto combustion method at low temperature (180 oC). The prepared samples were sintered at 500 oC for 4 hours. Single phase of these samples were confirmed by x-ray powder diffraction technique and found that lattice parameter increases with increasing with the Cobalt substituted concentration, and the values of crystallite size, x-ray density, bulk density and porosity of the prepared samples were calculated from the XRD analysis. The dc electrical resistivities of the prepared Li-Co ferrites were studied by using the two probe method in the temperature range of 473-873 K (200-600 oC). A plot of log (?T) vs inverse of temperature yields a almost straight line which reveals the semiconducting behavior of prepared ferrite samples. The dielectric properties namely dielectric constant (ε'), dielectric loss tangent (tan δ) of these Li-Co nano crystalline ferrites have been studied using an LCR meter from the room temperature to 700 K at various selected frequencies up to 5 MHz. The dielectric constant (ε') of all prepared samples was increased with increasing in temperature. These results have been explained on the basis of Koop’s theory, concentration of Fe+2 and Fe+3 ions on the octahedral site and hoping frequency of charge carriers (electrons) between Fe+2and Fe+3 ions.
Citrate gel method, nano ferrite, XRD studies, dc resistivity, dielectric properties.