Abstract
The dielectric parameters and ac electrical conductivity of Mg(0.8)Zn(0.2)CrxFe(2-x)O(4); (0 <= x <= 0.025) nanoferrites synthesized citrate-nitrate auto-combustion method were studied using the complex impedance technique in the frequency and temperature ranges 4 Hz-5 MHz and 303-873 K respectively. Hopping of charge carriers plus interfacial polarization could interpret the behaviors of dielectric constant (epsilon'), dielectric loss tangent (tan delta) and ac electrical conductivity (sigma(ac)) with frequency, temperatures and composition. The up-normal behavior observed in tand trend with temperatures confirms the presence of relaxation loss (dipoles losses). Correlated barrier hopping (CBH) of electron is the conduction mechanism of the investigated nanoferrites. Cole-Cole plots at different temperatures emphasize the main role of grain and grain boundaries in the properties of the investigated nanoferrites. Cr3+ substitution can control the dielectric parameters and ac electrical conductivity of Mg-Zn nanoferrites making it candidates for versatile applications.