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Updated: Jun 3, 2026

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
Published on: January 21, 2016
Determination of energy barrier distributions of magnetic nanoparticles by temperature dependent magnetorelaxometry
E Romanus1, D V Berkov, S Prass
1Ernst-Moritz-Arndt-Universität Greifswald, Institute of Pharmacy, F-L-Jahnstraße 17, 17487 Greifswald, Germany. Friedrich-Schiller-Universität Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
Abstract:
We present a new method for the characterization of magnetic nanoparticles based on the analysis of the dependence of the Néel relaxation signal on the sample temperature. In contrast to the established characterization methods, the new method directly delivers the energy barrier distribution of the magnetic system (in the case of ferrofluid particles or their aggregates). A water based ferrofluid consisting of magnetic nanoparticles with an iron oxide core and a shell of carboxydextran has been magnetically fractionated and immobilized and the fractions have been investigated in a temperature range from 77 to 350 K. The influence of the fractionation process on the distribution of the energy barriers of the particle system has been studied qualitatively.
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