Sharma, R. and Suri, K. and Tandon, R. P. and Annapoorni, S. and Lamba, S. and Kumaraswami, B. V. (2006) Magnetic relaxation studies in organic-inorganic nanoclusters. Journal of Applied Physics , 99 (024311). 024311-1-024311-6. ISSN 0021-8979

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Abstract

Inorganic/organic nanocomposites of iron oxide and polypyrrole, prepared by two different techniques, namely, simultaneous gelation/polymerization and polymerization over core iron oxide particles, were investigated for their structural and magnetic properties. The presence of the polymer was confirmed by Fourier transform infrared spectroscopy. The magnetic properties were found to be very sensitive not only to the concentration of polymer but also to the method of preparation. ac susceptibility measurements performed in the temperature range of 77-300 K show the signature of superparamagnetic behavior in both the systems. The blocking temperature was found to be dependent on the cluster size and interaction effects. The frequency variation of the blocking temperature in the samples prepared by simultaneous gelation and polymerization seems to indicate weakly interacting magnetic clusters, whereas in the samples prepared by polymerization around the core oxide particles, a strongly interacting signature is seen. ac susceptibility as calculated by kinetic Monte Carlo simulations based on an interacting model for single domain particles shows a qualitative agreement with the trends observed in the experimental results.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Institute of Physics.
Subjects:	Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	11 May 2018 07:01
Last Modified:	11 May 2018 07:01
URI:	http://npl.csircentral.net/id/eprint/2506

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