Temperature and frequency dependence on electrical properties of polyaniline/Ni(1−x)CoxFe2O4 nanocomposites

Two nanocomposites of polyaniline (PANI) varying in their percentage composition of Ni(1−x)CoxFe2O4 nanoparticle (20%, 10% w/w of fine powders) were prepared by in-situ chemical oxidative polymerization method with and without ultrasonic treatment. The spinel ferrite nanoparticles of chemical composition Ni(1−x)CoxFe2O4 were prepared by auto combustion method. The structure and morphology of PANI and nanocomposites were characterized by X-ray diffraction (XRD) and High resolution transmission electron microscopy (HRTEM). The chemical structure of Ni(1−x)CoxFe2O4 nanoparticles and its composites were characterized by using Fourier transform infrared (FTIR), UV-visible absorption spectrometer and XRD techniques. Dielectric properties of nanocomposites at different temperature have been performed in the frequency range of 50 Hz to 5 MHz. Dielectric constant, dielectric loss and AC conductivity of PANI/Ni(1−x)CoxFe2O4 nanocomposites are significantly increasing with increase in ferrite content due to the polaron/bipolaron formation. The optical absorption experiments of PANI/Ni(1−x)CoxFe2O4 nanocomposite illustrate a direct transition with an energy band gap of Eg around 1.7.