Dipolar interactions among magnetic dipoles of iron oxide particles dispersed in mili-size hydrogel beads

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dc.citation.journalTitleJOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
dc.contributor.authorActis, D.G.
dc.contributor.authorMuñoz Medina, G.A.
dc.contributor.authorVelásquez, A.A.
dc.contributor.authorPereda, C.
dc.contributor.authorSanchez, L.M.
dc.contributor.authorAlvarez, V.A.
dc.contributor.authorMuñetón Arboleda, D.
dc.contributor.authorMendoza Zélis, P.
dc.contributor.authorSánchez, F.H.
dc.contributor.departmentUniversidad EAFIT. Departamento de Ciencias Básicas
dc.contributor.researchgroupElectromagnetismo Aplicado (Gema)spa
dc.date.accessioned2021-03-23T21:39:34Z
dc.date.available2021-03-23T21:39:34Z
dc.date.issued2020-01-01
dc.description.abstractThe recently published Mean Field Interacting Superparamagnet Model (MFISP model), which introduces the effective demagnetizing factor NE, is tested in specimens having a random-like spatial distribution of magnetic nanoparticles, where different hierarchies of clustering are present. These specimens are ferrogel PVA/iron oxide beads synthesized by a one-pot route, having spheroidal shapes and sizes of about 1 mm, and chain and disk-like arrays (superstructures) of beads. Raman analyses indicated that magnetic nanoparticles are composed by a mixture of magnetite and maghemite. Beads swell 208% by hydration in about 40 min. The increase of the ac susceptibility as a function of hydration time closely reflects the effect of bead swelling, in agreement with the expected diminution of dipole–dipole interactions. Measured susceptibility is analyzed in terms of the susceptibility ? of non-interacting particles and the effective demagnetizing factor NE of the specimen, which depends on swelling. The Specific Absorption Rate of electromagnetic power by the beads grows with the hydration time in agreement with ac susceptibility behavior. For long hydration times susceptibility and high field magnetization decrease. This is explained by the occurrence of oxidation of magnetite/maghemite to hematite. Isothermal magnetization experiments are performed on each superstructure in two perpendicular principal directions each. Results are consistently described with the MFISP model by considering two hierarchies of clustering: beads themselves and clusters within the beads. From the whole set of experiments, it is possible to estimate values for the volume fractions of particles in clusters and clusters in beads, given by xpc=0.46(15) and xcb=0.16(5). The susceptibility of non-interacting particles, ?=13(4), is also obtained, which results about five times larger than the measured (apparent) one. The MFISP model proves to be a convenient and efficient tool for the analysis of magnetization studies of complex 3d dispersions of magnetic nanoparticles, allowing an experimental determination of relevant physical information, otherwise not accessible by magnetic measurements. © 2020 Elsevier B.V.eng
dc.identifierhttps://eafit.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=11920
dc.identifier.doi10.1016/j.jmmm.2020.166993
dc.identifier.issn03048853spa
dc.identifier.issn18734766spa
dc.identifier.otherWOS;000563928000003
dc.identifier.otherSCOPUS;2-s2.0-85086142755
dc.identifier.urihttp://hdl.handle.net/10784/27183
dc.language.isoengeng
dc.publisherElsevier B.V.
dc.relation.urihttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85086142755&doi=10.1016%2fj.jmmm.2020.166993&partnerID=40&md5=b6a2b835938c63652122836bc42efad4
dc.rightshttps://v2.sherpa.ac.uk/id/publication/issn/0304-8853
dc.sourceJOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
dc.subject.keywordHematiteeng
dc.subject.keywordHydrationeng
dc.subject.keywordMagnetic bubbleseng
dc.subject.keywordMagnetic susceptibilityeng
dc.subject.keywordMagnetiteeng
dc.subject.keywordMagnetite nanoparticleseng
dc.subject.keywordMagnetizationeng
dc.subject.keywordParticle size analysiseng
dc.subject.keywordDemagnetizing factorseng
dc.subject.keywordElectromagnetic powereng
dc.subject.keywordExperimental determinationeng
dc.subject.keywordHigh-field magnetizationeng
dc.subject.keywordIsothermal magnetizationeng
dc.subject.keywordNon-interacting particleseng
dc.subject.keywordPhysical informationeng
dc.subject.keywordSpecific absorption rateeng
dc.subject.keywordMagnetic nanoparticleseng
dc.titleDipolar interactions among magnetic dipoles of iron oxide particles dispersed in mili-size hydrogel beadseng
dc.typearticleeng
dc.typeinfo:eu-repo/semantics/articleeng
dc.typeinfo:eu-repo/semantics/publishedVersioneng
dc.typepublishedVersioneng
dc.type.localArtículospa

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