Table of Contents
ISRN Ceramics
Volume 2011, Article ID 194575, 8 pages
http://dx.doi.org/10.5402/2011/194575
Research Article

Microstructure Characterization of Nanocrystalline Magnesium Ferrite Annealed at Elevated Temperatures by Rietveld Method

1Department of Physics, The University of Burdwan, Golapbag, West Bengal, Burdwan 713104, India
2Department of Physics, Vivekananda College, West Bengal, Burdwan 713103, India

Received 17 August 2011; Accepted 20 September 2011

Academic Editors: H. I. Hsiang, W.-C. Oh, S. Shannigrahi, and S. Wongkasemjit

Copyright © 2011 Swapan Kumar Pradhan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nanocrystalline magnesium ferrite is synthesized at room temperature by high energy ball milling the MgO and α-Fe2O3 (1 : 1 mol fraction) powders. The Rietveld structure and microstructure refinements of X-ray powder diffraction data of 9 h milled sample reveal the presence of mixed and nearly inverse spinel nanocrystalline Mg-ferrite phases. Postannealing of nanocrystalline powder within 873–1473 K reveals continuous change in cation distribution among the tetrahedral and octahedral sites of mixed spinel lattice leading to nearly inverse spinel structure with increasing temperature. Mixed spinel structure finally transformed into inverse spinel structure after 1 h of annealing at 1073 K. The ferrite phase becomes completely stoichiometric by solid-state diffusion of unreacted (∼0.3 mol fraction) α-Fe2O3 into spinel lattice after 1 h of annealing at 1273 K. Interestingly, particle sizes of ferrite phases do not increase considerably up to 1073 K and increase suddenly after transformation of mixed spinel into nearly inverse spinel structure.