Abstract
The effect of compositional variation on the structural, and electromagnetic properties of Ni0.5Mg0.5-Fe2-xCrxO4 nanocrystalline ferrites (0 <= x <= 1.0) is presented. The ferrites were prepared by simple and environmental friendly sucrose assisted auto-combustion method with average crystallite size of 30-14 nm. The structure, morphology, magnetic and electrical properties of the samples were studied. XRD evidenced single-phase formation and exhibited a gradual decrease in the lattice parameters with increasing chromium. An appropriate cation distribution was then suggested and discussed based on the obtained structural, magnetic and electrical properties. The obtained results from the present study provided sufficient evidences that the successive replacing of Fe3+ ions by Cr3+ ions in the octahedral sites significantly affect both magnetization as well as the conductivity of the entire system. The acconductivity vs. temperature change indicated magnetic transition from ferro- to paramagnetic for samples with Cr-content <= 0.6 and a change in the conduction mechanism for samples with Cr-content x >= 0.8. The dielectric measurements confirmed these results and showed a gradual decrease with increasing frequency for all the samples. (C) 2019 Elsevier B.V. All rights reserved.