Enhancement in the dielectric and electrical properties of zirconium ferrite nanocrystalline ceramics with titanium substitution.

We report the effect of titanium doping on the structure, morphology, dielectric and electrical properties of zirconium ferrite Zr1−xTixFe2O4 (x = 0.0, 0.01, 0.03, 0.05) nanocrystalline ceramics prepared via sol–gel method. X-ray diffraction (XRD) technique confirmed the spinel structure of all samples and that the average crystallite size decreased with Ti doping. Scanning electron microscopy (SEM) confirmed the spherical-shaped morphology with an average grain size of 300 and 200 nm for x = 0 and 0.05, respectively. The Raman study revealed that Ti4+ substitution slightly shifts the Raman modes towards the lower wavenumber. The dielectric studies analyzed using Impedance analyzer show the increase in dielectric parameters such as dielectric constant and dielectric loss with Ti concentration. The complex impedance analysis in the frequency range (10–106 Hz) is analyzed to understand the interactions from the grain and grain boundary phases. The dielectric feedback and impedance analysis studied the electrical properties in the 300–700 K temperature range and frequency range of 20–106 Hz. The AC conductivity increases with applied frequency and decreases with doping concentration. It is found that the Ti concentration increases the activation energy determined using the Arrhenius equation of AC conductivity and is a characteristic of polaron conduction. The Universal power law dependency of AC conductivity indicates charge transport made possible by hopping or tunneling. The temperature-dependent frequency exponent n's observed minimal implies that the major transport mode is significant polaron tunneling. [ABSTRACT FROM AUTHOR]