Effect of alloying on the structure and electric properties of ZnFe<inf>2</inf>O<inf>4</inf>/ZnMn<inf>2</inf>O<inf>4</inf> heterostructure nanocomposites

Abstract

The heterostructure nanocomposite (1-x)ZnFe2O4/xZnMn2O4 (x = 0, 0.5, 0.8, 1) samples were prepared using the sol–gel method. The structural parameters and the percentages of the phases formed were determined utilizing the Rietveld method. Beside the two phases formed ZnFe2O4 (ZFO) and ZnMn2O4 (ZMO), a minor phase ZnO (3%) was observed in the sample x = 0.5. Analysis revealed phase percentages for composite samples different from intended (x) values due to the exchange of cations between the phases formed. The effect of composition ratio (x), as well as the frequency and temperature on the dielectric constant, dielectric loss, impedance spectroscopy and complex electric modulus and ac conductivity, was examined. The degree of correlation in each sample was also determined. Different conductivity mechanisms are found for different samples and frequency ranges. The 0.2ZFO-0.8ZMO sample disclosed higher conductivity and higher dispersion relative to other samples. The effect of temperature on the Cole–Cole plots was also studied.