Effect of doping of manganese ions on the structural and magnetic properties of nickel ferrite

We report the synthesis of Mn doped nickel ferrite having the generic formula Ni1-xMnxFe2O4 (x = 0.05, 0.10, 0.15) through chemical co-precipitation technique. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, dc magnetization studies and Mossbauer spectroscopy. XRD measurements showed the formation of pure spinel phase with particle size homogeneity. Rietveld refinement of the diffraction patterns using GSAS showed the presence of cationic vacancies in the sample. The analysis of the Williamson-Hall plot indicated the presence of strain in all the samples. Raman spectroscopy indicated the coexistence of an additional tetragonal phase P4(1)22 in addition to the cubic phase Fd (3) over barm in the samples. Dc magnetization studies showed the sample possessed negligible coercivity coupled with ferrimagnetic nature, corroborated by the Mossbauer measurement. The Mossbauer studies gave evidence of distortion in the crystal structure due to the dopant ions and the presence of cationic vacancies. The samples possessing low magnetocrystalline anisotropy along with ferrimagnetic behavior are a potential candidate for biomedical industries. (C) 2016 Elsevier B.V. All rights reserved.