Cation distribution and crystallographic characterization of the spinel oxides MgCrxFe2-xO4 by neutron diffraction
Journal article, 2015
The spinel system MgCrxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) has been prepared by solid state sintering method in air at 1573 K. X-ray and neutron powder diffraction experiments have been performed on the samples at room temperature for structural characterization. Rietveld refinement of the neutron diffraction data reveals that all the samples of the series possess cubic symmetry corresponding to the space group Fd-3m. The distribution of the three cations Mg, Fe and Cr over the two sublattices and other crystallographic parameters has been determined precisely. The results reveal that Cr has been substituted for Fe selectively. Cr ions invariably occupy the octahedral (B) site for all values of x. Mg and Fe ions are distributed over both A and B sites for all x values. With increasing x the occupation of Mg increases in the A site and decreases in the B site for all the samples, while the Fe ions gradually decreases in both the sites for all values of x. The lattice constant decreases with increasing Cr content in the system. The magnetic structure at room temperature was ferrimagnetic for all the samples.
Ferrimagnetic
Ferrite
Neutron diffraction
Crystal structure
Spinel structure
Author
A. K. M. Zakaria
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
F. Nesa
Daffodil International University
Jahangirnagar University
M. A. S. Khan
Jahangirnagar University
T. K. Datta
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
S. Aktar
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
S. I. Liba
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
S. Hossain
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
A. K. Das
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
I. Kamal
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
S. M. Yunus
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment
Sten Eriksson
Chalmers, Chemistry and Chemical Engineering, Energy and Material
Journal of Alloys and Compounds
0925-8388 (ISSN)
Vol. 633 115-119Subject Categories
Physical Chemistry
DOI
10.1016/j.jallcom.2015.01.179