McGhie, A, Marquina, C, O'Grady, Kevin Dermot orcid.org/0000-0002-4837-3709 et al. (1 more author) (2017) Measurement of the distribution of anisotropy constants in magnetic nanoparticles for hyperthermia applications. Journal of Physics D: Applied Physics. 455003. ISSN 1361-6463
Abstract
In this work we have applied theoretical calculations to new experimental measurements of the effect of the anisotropy distribution in magnetite nanoparticles which in turn controls hysteresis heating for hyperthermia applications. Good agreement between theory and experiment is reported where the theoretical calculation is based upon the detailed measurement of the particle elongation generally observed in the nanoparticles. The elongation has been measured from studies via transmission electron microscopy (TEM). We find that particle elongation is responsible for the anisotropy dispersion which can be obtained by analysis and fitting to a measurement of the temperature decay of remanence. A median value of the anisotropy constant of 1.5x105erg/cc was obtained. A very wide distribution of anisotropy constants is present with a Gaussian standard deviation of 1.5x105erg/cc. From our measurements, deviations in the value of the saturation magnetisation from particle to particle are most likely the main factor giving rise to this large distribution with 33% arising from the error in the measured elongation. The lower limit to the anisotropy constant of the nanoparticles is determined by the magnetocrystalline anisotropy of the material, 1.1x105erg/cc for magnetite which was studied in this work.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017, IOP Publishing Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) |
Depositing User: | Pure (York) |
Date Deposited: | 10 Apr 2018 15:50 |
Last Modified: | 13 Feb 2025 05:25 |
Status: | Published |
Refereed: | Yes |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:129512 |
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Description: Measurement of the distribution of anisotropy constants in magnetic nanoparticles for hyperthermia application