Abstract
Cobalt doped nickel ferrites were fabricated by sol gel route and the dielectric constant, tangent loss and AC conductivity were investigated as a function of Co doping. The X-ray diffractometer characterization confirmed that the CoxNi1-xFe2O4 with doping concentration (x = 0.1, 0.2, 0.3, 0.4, and 0.5) have cubic spinel structure. In the XRD spectrum there appear extra peaks of Fe2O3 as an impurity that is gradually disappear by increasing doping ratio of cobalt ions, which is an indication of high crystallinity. The structural parameters (lattice constant, grain size, dislocation density, X-rays density and packing factor) are greatly influenced by the doping of cobalt atoms i.e., lattice constant increases. The crystal size increases from 30 to 42.26 nm by cobalt substitution in the pure nickel ferrites. The Fourier Transform IR Spectroscopy indicate shift in peaks to lower frequency region because cobalt doping reduced binding energy between metal ion and oxygen ions. Atomic structure of cobalt doped nickel ferrites examined by the Raman spectroscopy. CoxNi1-xFe2O4 shows Raman mode at similar to 285, similar to 477, similar to 563, similar to 624 and similar to 704 cm(-1). There is unnoticeable Raman shift due to the doping of cobalt's atoms.