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Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters

Understanding magnetic interparticle interactions within a single hydrodynamic volume of polydispersed magnetic nanoparticles and the resulting nonlinear magnetization properties is critical for their implementation in magnetic theranostics. However, in general, the field-dependent static and dynami...

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Detalles Bibliográficos
Autores principales: Trisnanto, Suko Bagus, Takemura, Yasushi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027232/
https://www.ncbi.nlm.nih.gov/pubmed/29891808
http://dx.doi.org/10.3390/nano8060424
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author Trisnanto, Suko Bagus
Takemura, Yasushi
author_facet Trisnanto, Suko Bagus
Takemura, Yasushi
author_sort Trisnanto, Suko Bagus
collection PubMed
description Understanding magnetic interparticle interactions within a single hydrodynamic volume of polydispersed magnetic nanoparticles and the resulting nonlinear magnetization properties is critical for their implementation in magnetic theranostics. However, in general, the field-dependent static and dynamic magnetization measurements may only highlight polydispersity effects including magnetic moment and size distributions. Therefore, as a complement to such typical analysis of hysteretic magnetization curves, we spectroscopically examined the complex magnetization harmonics of magnetic nanoclusters either dispersed in a liquid medium or immobilized by a hydrocolloid polymer, later to emphasize the harmonic characteristics for different core sizes. In the case of superparamagnetic nanoclusters with a 4-nm primary size, particularly, we correlated the negative quadrature components of the third-harmonic susceptibility with an insignificant cluster rotation induced by the oscillatory field. Moreover, the field-dependent in-phase components appear to be frequency-independent, suggesting a weak damping effect on the moment dynamics. The characteristic of the Néel time constant further supports this argument by showing a smaller dependence on the applied dc bias field, in comparison to that of larger cores. These findings show that the complex harmonic components of the magnetization are important attributes to the interacting cores of a magnetic nanocluster.
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spelling pubmed-60272322018-07-13 Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters Trisnanto, Suko Bagus Takemura, Yasushi Nanomaterials (Basel) Article Understanding magnetic interparticle interactions within a single hydrodynamic volume of polydispersed magnetic nanoparticles and the resulting nonlinear magnetization properties is critical for their implementation in magnetic theranostics. However, in general, the field-dependent static and dynamic magnetization measurements may only highlight polydispersity effects including magnetic moment and size distributions. Therefore, as a complement to such typical analysis of hysteretic magnetization curves, we spectroscopically examined the complex magnetization harmonics of magnetic nanoclusters either dispersed in a liquid medium or immobilized by a hydrocolloid polymer, later to emphasize the harmonic characteristics for different core sizes. In the case of superparamagnetic nanoclusters with a 4-nm primary size, particularly, we correlated the negative quadrature components of the third-harmonic susceptibility with an insignificant cluster rotation induced by the oscillatory field. Moreover, the field-dependent in-phase components appear to be frequency-independent, suggesting a weak damping effect on the moment dynamics. The characteristic of the Néel time constant further supports this argument by showing a smaller dependence on the applied dc bias field, in comparison to that of larger cores. These findings show that the complex harmonic components of the magnetization are important attributes to the interacting cores of a magnetic nanocluster. MDPI 2018-06-11 /pmc/articles/PMC6027232/ /pubmed/29891808 http://dx.doi.org/10.3390/nano8060424 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Trisnanto, Suko Bagus
Takemura, Yasushi
Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title_full Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title_fullStr Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title_full_unstemmed Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title_short Complex Magnetization Harmonics of Polydispersive Magnetic Nanoclusters
title_sort complex magnetization harmonics of polydispersive magnetic nanoclusters
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027232/
https://www.ncbi.nlm.nih.gov/pubmed/29891808
http://dx.doi.org/10.3390/nano8060424
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