Effect of Ag on Dielectric and Electrical Properties of Spinel Cobalt Ferrite

Abstract

In this study we took Co-precipitation chemical route to synthesize CoFe2O4 nanoparticles and loaded this with Silver one of the most electrically conductive materials as AgxCo1-xFe2O4 to study the effect occurred in its Electric and Dielectric properties in the presence of silver at different concentrations. XRD patterns confirmed the formation of pure CoFe2O4 and AgxCo1-xFe2O4 nanoparticles at x= 0.20, 0.35, 0.50 The average crystallite size found for pure CoFe2O4 nanoparticles was 31nm while for Silver loaded it is in the range from 34 to 44 nm. SEM shows uniformly distributed homogenous spherical nanoparticles grown by co-precipitation method. FTIR results confirmed the absorption peaks for CoFe2O4 and AgxCo1-xFe2O4 nanoparticles in the range 550-600 cm-1 and 380-450 cm-1. Which confirms the presence of tetrahedral and octahedral sites in spinel ferrite structure. The dielectric parameters were studied and dielectric constant (ε’), dielectric loss (ε”), dielectric loss tangent (tan δ) decreases with increase in frequency and increases with increase in concentration x of silver in CoFe2O4 and these properties enhanced promisingly. Impedance decrease with increase of concentration of conductive metal silver offering more electrons to move between the cations. The A.C conductivity is maximum at higher frequency which represent the dominance of hoping conductivity over band conductivity. The electric modulus increases with increase in frequency and decreases with increase in concentrations of silver in CoFe2O4. The Cole-Cole plot of electric modulus gives semi circles curves and relaxation time at higher frequencies. The resistivity “lnρ” of the prepared samples was plotted against “1/kBT”. A decrease in DC electrical resistivity with increase in temperature has been observed. These variations in the Electric and Dielectric properties of CoFe2O4 due to silver made it an important material for the electromagnetic devices and biomedical applications.