Mossbauer study of chromium-substituted nickel ferrites

The structural and magnetic properties of the Cr substituted NiCrxFe1-xO4 (0 <= x <= 1.4) spine] ferrites have been investigated by means of X-ray diffraction and Mossbauer spectroscopy techniques. Their crystal structures are found to be pure cubic phases. The Mossbauer spectra at 295 and 78 K of all samples showed two well-resolved magnetic patterns corresponding to the tetrahedral A-sites and octahedral B-sites. The cation distributions driven from the area under resonance curve of each site revealed that the compounds are gradually transferred from perfect inverse spinel to partially normal spinel structure. The behavior of the magnetic properties as a function of Cr3+ concentration has been explained on the basis of the driven cation distribution and it showed that the chrome-rich compositions can be explained in terms of the non-collinear spin model. (c) 2005 Elsevier B.V. All rights reserved.