Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS

When a uniaxial magnetic field is applied to a non-magnetic dispersive medium filled with magnetic nanoparticles, they auto-assemble into thin needles parallel to the field direction, due to the strong dipolar interaction among them. We have prepared in this way magnetically oriented nanocomposites...

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Detalles Bibliográficos
Autores principales: Antonel, Paula Soledad, Negri, Ricardo Martin, Jorge, Guillermo Antonio
Publicado: 2012
Materias:
Magnetic anisotropy
Magnetic viscosity
Magnetoelastomers
Relaxation
Dipolar interaction
Dispersive medium
Field directions
Local magnetic anisotropy
Logarithmic relaxation
Magnetic nanoparticles
Magnetic particle
Nanometer size
Nonmagnetics
Polydimethylsiloxane polymers
Magnetic fields
Needles
Relaxation processes
Silicones
Nanoparticles
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09214526_v407_n16_p3165_Antonel
http://hdl.handle.net/20.500.12110/paper_09214526_v407_n16_p3165_Antonel
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_09214526_v407_n16_p3165_Antonel
record_format dspace
spelling paper:paper_09214526_v407_n16_p3165_Antonel2023-06-08T15:50:37Z Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS Antonel, Paula Soledad Negri, Ricardo Martin Jorge, Guillermo Antonio Magnetic anisotropy Magnetic viscosity Magnetoelastomers Relaxation Dipolar interaction Dispersive medium Field directions Local magnetic anisotropy Logarithmic relaxation Magnetic nanoparticles Magnetic particle Magnetic viscosity Magnetoelastomers Nanometer size Nonmagnetics Polydimethylsiloxane polymers Relaxation Magnetic anisotropy Magnetic fields Needles Relaxation processes Silicones Nanoparticles When a uniaxial magnetic field is applied to a non-magnetic dispersive medium filled with magnetic nanoparticles, they auto-assemble into thin needles parallel to the field direction, due to the strong dipolar interaction among them. We have prepared in this way magnetically oriented nanocomposites of nanometer-size CoFe 2O 4 particles in a polydimethylsiloxane polymer matrix, with 10% w/w of magnetic particles. We present the characteristic magnetic relaxation curves measured after the application of a magnetic field forming an angle α with respect to the needle direction. We show that the magnetic viscosity (calculated from the logarithmic relaxation curves) as a function of α presents a minimum at α=0, indicating slower relaxation processes associated with this configuration of fields. The results seems to point out that the local magnetic anisotropy of the nanoparticles is oriented along the needles, resulting in the macroscopic magnetic anisotropy observed in our measurements. © 2011 Elsevier B.V. All rights reserved. Fil:Antonel, P.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Negri, R.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Jorge, G.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09214526_v407_n16_p3165_Antonel http://hdl.handle.net/20.500.12110/paper_09214526_v407_n16_p3165_Antonel
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Magnetic anisotropy
Magnetic viscosity
Magnetoelastomers
Relaxation
Dipolar interaction
Dispersive medium
Field directions
Local magnetic anisotropy
Logarithmic relaxation
Magnetic nanoparticles
Magnetic particle
Magnetic viscosity
Magnetoelastomers
Nanometer size
Nonmagnetics
Polydimethylsiloxane polymers
Relaxation
Magnetic anisotropy
Magnetic fields
Needles
Relaxation processes
Silicones
Nanoparticles
spellingShingle Magnetic anisotropy
Magnetic viscosity
Magnetoelastomers
Relaxation
Dipolar interaction
Dispersive medium
Field directions
Local magnetic anisotropy
Logarithmic relaxation
Magnetic nanoparticles
Magnetic particle
Magnetic viscosity
Magnetoelastomers
Nanometer size
Nonmagnetics
Polydimethylsiloxane polymers
Relaxation
Magnetic anisotropy
Magnetic fields
Needles
Relaxation processes
Silicones
Nanoparticles
Antonel, Paula Soledad
Negri, Ricardo Martin
Jorge, Guillermo Antonio
Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
topic_facet Magnetic anisotropy
Magnetic viscosity
Magnetoelastomers
Relaxation
Dipolar interaction
Dispersive medium
Field directions
Local magnetic anisotropy
Logarithmic relaxation
Magnetic nanoparticles
Magnetic particle
Magnetic viscosity
Magnetoelastomers
Nanometer size
Nonmagnetics
Polydimethylsiloxane polymers
Relaxation
Magnetic anisotropy
Magnetic fields
Needles
Relaxation processes
Silicones
Nanoparticles
description When a uniaxial magnetic field is applied to a non-magnetic dispersive medium filled with magnetic nanoparticles, they auto-assemble into thin needles parallel to the field direction, due to the strong dipolar interaction among them. We have prepared in this way magnetically oriented nanocomposites of nanometer-size CoFe 2O 4 particles in a polydimethylsiloxane polymer matrix, with 10% w/w of magnetic particles. We present the characteristic magnetic relaxation curves measured after the application of a magnetic field forming an angle α with respect to the needle direction. We show that the magnetic viscosity (calculated from the logarithmic relaxation curves) as a function of α presents a minimum at α=0, indicating slower relaxation processes associated with this configuration of fields. The results seems to point out that the local magnetic anisotropy of the nanoparticles is oriented along the needles, resulting in the macroscopic magnetic anisotropy observed in our measurements. © 2011 Elsevier B.V. All rights reserved.
author Antonel, Paula Soledad
Negri, Ricardo Martin
Jorge, Guillermo Antonio
author_facet Antonel, Paula Soledad
Negri, Ricardo Martin
Jorge, Guillermo Antonio
author_sort Antonel, Paula Soledad
title Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
title_short Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
title_full Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
title_fullStr Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
title_full_unstemmed Anisotropy and relaxation processes of uniaxially oriented CoFe 2O 4 nanoparticles dispersed in PDMS
title_sort anisotropy and relaxation processes of uniaxially oriented cofe 2o 4 nanoparticles dispersed in pdms
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09214526_v407_n16_p3165_Antonel
http://hdl.handle.net/20.500.12110/paper_09214526_v407_n16_p3165_Antonel
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AT negriricardomartin anisotropyandrelaxationprocessesofuniaxiallyorientedcofe2o4nanoparticlesdispersedinpdms
AT jorgeguillermoantonio anisotropyandrelaxationprocessesofuniaxiallyorientedcofe2o4nanoparticlesdispersedinpdms
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