Structural analysis and role of cation distribution on the magnetic properties of single phase Ni-doped copper chromium ferrite

• Published in: Journal of materials science. Materials in electronics Vol. 30; no. 22; pp. 20099 - 20108
• Main Authors: Moustafa, A. M., Farag, I. S. Ahmed, Abdellatif, M. H., Ahmed, M. A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-11-2019; Springer Nature B.V
• Subjects: Cations; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chromium; Copper; Crystallites; Curie temperature; Doping; Ferrites; Magnetic measurement; Magnetic moments; Magnetic permeability; Magnetic properties; Magnetism; Materials Science; Microstrain; Nickel; Optical and Electronic Materials; Site preference (crystals); Spinel; Structural analysis; Unit cell
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-019-02384-9

A series of single-phase spinel structure was prepared by the standard ceramic technique in order to study the effect of cation doping on the microstructure and magnetic properties of spinel ferrite. We have used six Ni concentrations in the doping process of mixed spinel (Mg, Cu, Cr ferrite). Single-phase formation for all the prepared samples was confirmed using X-ray diffraction. Rietveled refinement was applied to study the structural characteristics and the cation distribution of the compounds. The refined data showed that the Mg cations have tetrahedral site preference, while Ni and Cr cations prefer the octahedral site. Hence replacing Ni cation by Mg cation forces the structure to be normal spinel. With increasing Ni content the unit cell dimension decreases and the degree of inversion increases. Accordingly the microstrain decreases, while the crystallite size tend to increase as Ni content increases. From the magnetic measurements it was found that, the magnetic susceptibility decreases with increasing temperature which revealed the normal behaviour of the spinel ferrite. The Curie temperature was found to increase with increasing the Ni content. The impressive results obtained were the decrease of the effective magnetic moment and the exchange interaction constant J
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with increasing Ni content. The results show that the magnetic nature of the doping element does not play a major role in determining the final magnetic properties of the compound. Instead, the cation distribution is the significant parameter.