Anantharaman, M R; Swapna, Nair S; Mercy, Mathews; Joy, P A; Kulkarni, S D(Elsevier, July 26, 2004)
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Abstract:
Superparamagnetic nanocomposites based on g-Fe2O3 and sulphonated polystyrene have been synthesized by ion
exchange process and the preparation conditions were optimized. Samples were subjected to cycling to study the effect
of cycling on the magnetic properties of these composites. The structural and magnetization studies have been carried
out. Magnetization studies show the dependence of magnetization on the number of ion exchange cycles. Doping of
cobalt at the range in to the g-Fe2O3 lattice was effected in situ and the doping was varied in the atomic percentage
range 1–10. The exact amount of cobalt dopant as well as the iron content was estimated by Atomic Absorption
Spectroscopy. The effect of cobalt in modifying the properties of the composites was then studied and the results
indicate that the coercivity can be tuned by the amount of cobalt in the composites. The tuning of both the
magnetization and the coercivity can be achieved by a combination of cycling of ion exchange and the incorporation of
cobalt
Description:
Journal of Magnetism and Magnetic Materials 283 (2004) 344–352
Anantharaman, M R; Malini, K A; Ajay, Gupta(Springer, June 14, 2004)
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Abstract:
Nanocomposites with magnetic components possessing nanometric dimensions, lying in the range
1–10 nm, are found to be exhibiting superior physical properties with respect to their coarser sized counterparts.
Magnetic nanocomposites based on gamma iron oxide embedded in a polymer matrix have been prepared
and characterized. The behaviour of these samples at low temperatures have been studied using Mössbauer
spectroscopy. Mössbauer studies indicate that the composites consist of very fine particles of g-Fe2O3 of which
some amount exists in the superparamagnetic phase. The cycling of the preparative conditions were found to
increase the amount of g-Fe2O3 in the matrix
Description:
Bull. Mater. Sci., Vol. 27, No. 4, August 2004, pp. 361–366