Study of the Crystallographic and Magnetic Structure in the Nickel Substituted Cobalt Ferrites by Neutron Diffraction

Abstract

How to cite this paper: Khanam, S., et al. (2015) Study of the Crystallographic and Magnetic Structure in the Nickel Substi-tuted Cobalt Ferrites by Neutron Diffraction. Materials Sciences and Applications, 6, 332-342. Abstract The polycrystalline spinel oxides NixCo1−xFe2O4 with composition x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were prepared by conventional solid state ceramic sintering technique in air at 1300°C. X-ray dif-fraction experiments were carried out on all the samples at room temperature in order to charac-terize the materials. X-ray diffraction patterns showed sharp peaks indicating the formation of single phase cubic spinel structure. The neutron diffraction experiments were performed on all samples at room temperature, with an incident monochromatic neutron beam of wavelength λ = 1.5656 Å. The experimental neutron diffraction data were analyzed using the computer program FullProf in the Reitveld method. Reitveld refinement of the neutron diffraction data reveals that the samples possess cubic symmetry corresponding to the space group F d-3m. Cation distribution between the two sublattices of the spinel structure has been found from the analysis of the neu-tron diffraction data. Lattice parameters, oxygen position parameters, and overall temperature factors have also been determined from the analysis of neutron diffraction data. The lattice para-meter decreases and oxygen position parameter increases with increasing Ni content in the sys-tem. Sublattices and net magnetic moments have been determined from the refinement of neutron diffraction data. The magnetic structure at room temperature was found to be ferrimagnetic for all the samples.