Cation distribution in Ni-substituted Mn0.5Zn0.5Fe2O4 nanoparticles: A Raman, Mossbauer, X-ray diffraction and electron spectroscopy study

In this paper we report the structural, vibration, and electronic-structure parameters (bonding and valence of cations) of single phase cubic mixed spinel nanoparticles of (Zn delta Mn gamma Fe1-(gamma+delta))[NixZn0.5-delta Mn0.5-gamma-chi Fe1+(gamma+delta)]O-4 where x=0.05-0.45 with an aim to determine cation-distribution i.e. delta and gamma in these samples. The Raman spectroscopy has established that only Fe and Zn cations occupy tetrahedral interstitial sites in a FCC anion lattice in nearly equal fraction, and Mossbauer spectra have shown that Fe3+ cations are present at both, tetrahedral and octahedral interstitial sites and Ni2+ cations are situated at the octahedral sites in all the substituted samples. The photoelectron spectra also revealed the presence of Fe3+ cations at both the interstitial sites. The best possible cationic distribution in Ni substituted Mn-Zn ferrites has been estimated by reiteratively calculating the intensity ratios of various pairs of X-ray diffraction peaks and matching with the observed intensity ratios. (C) 2016 Elsevier B.V. All rights reserved.