Comparative study of behavior of electrical conductivity in KI‒Al2O3 and KI‒TiO2 heterostructure composites

Abstract

The present work reports development of binary KI–Al2O3 and KI–TiO2-based nanocomposites using simple solid-state reaction method and is characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. The results show the effect of heterogeneously doped Al2O3 and TiO2 on the ionic conductivity of pure KI which is moderately conductive. The results supported the composite development in which the interface layer portrays a significant part in governing the bulk properties of the compound. Improvement in electrical conductivity is seen in the incorporation of Al2O3 and TiO2 dispersoid into the matrix of KI. With temperature, electrical conductivity increased and the activation energies were found to be decreasing. The activation energies for KI–Al2O3 and KI–TiO2 systems were 0.22 eV and 0.21 eV, respectively, in the temperature range 20‒400 °C. Dielectric constant increases with the increase in temperature in the entire temperature range studied attributed to the phenomenon of distortion of electric charges.