Investigation of the dielectric and impedance properties of ZnO/MgO nanocomposite

The present work deals with the feasibility of incorporating the oxides of Zn and Mg for the high-frequency electronic devices and for that the ZnO/MgO nanocomposites with different Mg ratios formed by the sol-gel method were analyzed thoroughly for the physical characteristics. The powdered X-ray diffraction (XRD) was used for the investigation of crystallinity and structure, while the High-resolution scanning electron microscope (HRSEM) for the size, shape, and surface morphology. Further, for the analysis of ZnO/MgO nanocomposite's dielectric properties, a suitable complex impedance technique set at different frequencies in the range of 100 Hz-5 MHz and various temperatures of around 306-723 K was used. The AC conductivity of ZnO/MgO nanocomposite was explained based on the VRH model and is investigated to follow the Jonscher power law, sigma(AC)(omega) = A omega(s) and the value of frequency exponent (s) are calculated to be less than unity. The temperature dependence of conductivity (sigma(AC)) shows that it is a thermally activated process and hence the synthesized ZnO/MgO nanocomposite exhibits the semiconductor behavior. The activation energy of the synthesized nanocomposite calculated using the Arrhenius plot indicated that the values are getting decreased with that of increased frequency.