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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-24 22:09 |
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Conference: Bucharest University Faculty of Physics 2015 Meeting
Section: Solid State Physics and Materials Science
Title:
Observations of modified superparamagnetic behavior of iron-oxide nanoparticles by calorimetric measurements
Authors:
N.IACOB (1,3), G.SCHINTEIE (2), C. BARTHA (2), V.KUNCSER (2)
Affiliation:
(1) National Institute for Laser, Plasma and Radiation Physics, 077125, Bucharest, Romania
(2) National Institute of Materials Physics, PO Box MG-7, 077125 Bucharest-Magurele, Romania
3 University of Bucharest, Department of Physics, 077125, Bucharest, Romania
E-mail
niacob_ro@yahoo.com
Keywords:
Magnetic nanoparticles, magnetic hyperthermia, magnetic interactions
Abstract:
The changes produced in the superparamagnetic behavior of a nanoparticulate system due to inter-particle interactions can be very complex, being intensively treated by many authors [1-3]. Such interactions may have important effects and for example could influence the magnetic response of nanoparticulate systems for bio-medical applications. A special case concerns the magnetic fluid hyperthermia (MFH), where possible accumulation of high nanoparticle concentrations in biological tissues will affects the magnetic relaxation processes responding for heat dissipation. In MFH, magnetic nanoparticles are dispersed in a liquid, being covered with an organic surfactant in order to avoid particle agglomeration. In this respect, only magnetic diplar interactions (long-range interactions) are present in the system. Using a superparamagnetic model [4] which quantifies the response of nanoparticles to excitation with AC magnetic fields corroborated with suitable calorimetric measurements, a quantitative analysis of the superparamagnetic relaxation behavior of ferrofluid samples with different volume fractions (and implicitly inter-particle interactions) is reported.
References:
[1] J. L. Dormann, D. Fiorani and E. Tronc, “Magnetic Relaxation In Fine-Particle Systems”, Advances in Chemical Physics, Volume XCVIII, Edited by I. Prigogine and Stuart A. Rice. ISBN 0-471-16285-X 0 1997 John Wiley & Sons, Inc.
[2] Subhankar Bedanta and Wolfgang Kleemann, “Supermagnetism”, J. Phys. D: Appl. Phys.42(2009) 013001 (28pp)
[3] O. Petracic, “Superparamagnetic nanoparticle ensembles”, Superlattices and Microstructures 47 (2010) 569 578
[4] R. E. Rosensweig,“Heating magneticfluid with alternating magnetic field,”J. Magn. Magn. Mater., vol. 252, pp. 370–374, 2002
Acknowledgement:
Nicusor Iacob was supported by the strategic grant POSDRU/159/1.5/S/137750, ”Project Doctoral and Postdoctoral programs support for increased competitiveness in Exact Sciences research” cofinanced by the European Social Found within the Sectorial Operational Program Human Resources Development 2007 – 2013.
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