Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles

Autores
Lavorato, Gabriel Carlos; Winkler, Elin Lilian; Ghirri, Alberto; Lima, Enio Junior; Peddis, Davide; Troiani, Horacio Esteban; Fiorani, Dino; Agostinelli, Elisabetta; Rinaldi, Daniele; Zysler, Roberto Daniel
Año de publicación
2016
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Bimagnetic nanoparticles have been proposed for the design of new materials with controlled properties, which requires a comprehensive investigation of their magnetic behavior due to multiple effects arising from their complex structure. In this work we fabricated bimagnetic core/shell nanoparticles formed by an ∼3-nm antiferromagnetic (AFM) CoO core encapsulated within an ∼1.5-nm ferrimagnetic (FiM) Co0.5Ni0.5Fe2O4 shell, aiming at studying the enhancement of the magnetic anisotropy and the surface effects of a ferrimagnetic oxide shell. The magnetic properties of as-synthesized and annealed samples were analyzed by ac and dc magnetization measurements. The results indicate that the magnetic response of the as-synthesized particles is governed by the superparamagnetic behavior of the interacting nanoaggregates of spins that constitute the disordered ferrimagnetic shell, whose total moments block at (TB)=49 K and collectively freeze in a superspin-glass-type state at (Tg)=3 K. On the other hand, annealed nanoparticles are superparamagnetic at room temperature and behave as an exchange-coupled system below the blocking temperature (TB)=70 K, with enhanced coercivity HC(10K)∼14.6 kOe and exchange bias field HEB(10K)∼2.3 kOe, compared with the as-synthesized system where HC(10K)∼5.5 kOe and HEB(10K)∼0.8 kOe. Our results, interpreted using different models for thermally activated and surface relaxation processes, can help clarify the complex magnetic behavior of many core/shell and hollow nanoparticle systems.
Fil: Lavorato, Gabriel Carlos. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Winkler, Elin Lilian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Ghirri, Alberto. Consiglio Nazionale delle Ricerche; Italia
Fil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Peddis, Davide. Consiglio Nazionale delle Ricerche; Italia
Fil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Fiorani, Dino. Consiglio Nazionale delle Ricerche; Italia
Fil: Agostinelli, Elisabetta. Consiglio Nazionale delle Ricerche; Italia
Fil: Rinaldi, Daniele. Universita Politecnica delle Marche via Brecce Bianche; Italia
Fil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Materia
CORE/SHELL NANOPARTICLES
EXCHANGE-BIAS
MAGNETIC NANOPARTICLES
FERRITES
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/126149
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/126149
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticlesLavorato, Gabriel CarlosWinkler, Elin LilianGhirri, AlbertoLima, Enio JuniorPeddis, DavideTroiani, Horacio EstebanFiorani, DinoAgostinelli, ElisabettaRinaldi, DanieleZysler, Roberto DanielCORE/SHELL NANOPARTICLESEXCHANGE-BIASMAGNETIC NANOPARTICLESFERRITEShttps://purl.org/becyt/ford/2.10https://purl.org/becyt/ford/2https://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Bimagnetic nanoparticles have been proposed for the design of new materials with controlled properties, which requires a comprehensive investigation of their magnetic behavior due to multiple effects arising from their complex structure. In this work we fabricated bimagnetic core/shell nanoparticles formed by an ∼3-nm antiferromagnetic (AFM) CoO core encapsulated within an ∼1.5-nm ferrimagnetic (FiM) Co0.5Ni0.5Fe2O4 shell, aiming at studying the enhancement of the magnetic anisotropy and the surface effects of a ferrimagnetic oxide shell. The magnetic properties of as-synthesized and annealed samples were analyzed by ac and dc magnetization measurements. The results indicate that the magnetic response of the as-synthesized particles is governed by the superparamagnetic behavior of the interacting nanoaggregates of spins that constitute the disordered ferrimagnetic shell, whose total moments block at (TB)=49 K and collectively freeze in a superspin-glass-type state at (Tg)=3 K. On the other hand, annealed nanoparticles are superparamagnetic at room temperature and behave as an exchange-coupled system below the blocking temperature (TB)=70 K, with enhanced coercivity HC(10K)∼14.6 kOe and exchange bias field HEB(10K)∼2.3 kOe, compared with the as-synthesized system where HC(10K)∼5.5 kOe and HEB(10K)∼0.8 kOe. Our results, interpreted using different models for thermally activated and surface relaxation processes, can help clarify the complex magnetic behavior of many core/shell and hollow nanoparticle systems.Fil: Lavorato, Gabriel Carlos. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Winkler, Elin Lilian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Ghirri, Alberto. Consiglio Nazionale delle Ricerche; ItaliaFil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Peddis, Davide. Consiglio Nazionale delle Ricerche; ItaliaFil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Fiorani, Dino. Consiglio Nazionale delle Ricerche; ItaliaFil: Agostinelli, Elisabetta. Consiglio Nazionale delle Ricerche; ItaliaFil: Rinaldi, Daniele. Universita Politecnica delle Marche via Brecce Bianche; ItaliaFil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaAmerican Physical Society2016-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/126149Lavorato, Gabriel Carlos; Winkler, Elin Lilian; Ghirri, Alberto; Lima, Enio Junior; Peddis, Davide; et al.; Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles; American Physical Society; Physical Review B; 94; 5; 8-2016; 544321-5443292469-9969CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.054432info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.94.054432info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:01:32Zoai:ri.conicet.gov.ar:11336/126149instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 10:01:32.472CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
title Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
spellingShingle Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
Lavorato, Gabriel Carlos
CORE/SHELL NANOPARTICLES
EXCHANGE-BIAS
MAGNETIC NANOPARTICLES
FERRITES
title_short Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
title_full Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
title_fullStr Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
title_full_unstemmed Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
title_sort Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles
dc.creator.none.fl_str_mv Lavorato, Gabriel Carlos
Winkler, Elin Lilian
Ghirri, Alberto
Lima, Enio Junior
Peddis, Davide
Troiani, Horacio Esteban
Fiorani, Dino
Agostinelli, Elisabetta
Rinaldi, Daniele
Zysler, Roberto Daniel
author Lavorato, Gabriel Carlos
author_facet Lavorato, Gabriel Carlos
Winkler, Elin Lilian
Ghirri, Alberto
Lima, Enio Junior
Peddis, Davide
Troiani, Horacio Esteban
Fiorani, Dino
Agostinelli, Elisabetta
Rinaldi, Daniele
Zysler, Roberto Daniel
author_role author
author2 Winkler, Elin Lilian
Ghirri, Alberto
Lima, Enio Junior
Peddis, Davide
Troiani, Horacio Esteban
Fiorani, Dino
Agostinelli, Elisabetta
Rinaldi, Daniele
Zysler, Roberto Daniel
author2_role author
author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv CORE/SHELL NANOPARTICLES
EXCHANGE-BIAS
MAGNETIC NANOPARTICLES
FERRITES
topic CORE/SHELL NANOPARTICLES
EXCHANGE-BIAS
MAGNETIC NANOPARTICLES
FERRITES
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.10
https://purl.org/becyt/ford/2
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Bimagnetic nanoparticles have been proposed for the design of new materials with controlled properties, which requires a comprehensive investigation of their magnetic behavior due to multiple effects arising from their complex structure. In this work we fabricated bimagnetic core/shell nanoparticles formed by an ∼3-nm antiferromagnetic (AFM) CoO core encapsulated within an ∼1.5-nm ferrimagnetic (FiM) Co0.5Ni0.5Fe2O4 shell, aiming at studying the enhancement of the magnetic anisotropy and the surface effects of a ferrimagnetic oxide shell. The magnetic properties of as-synthesized and annealed samples were analyzed by ac and dc magnetization measurements. The results indicate that the magnetic response of the as-synthesized particles is governed by the superparamagnetic behavior of the interacting nanoaggregates of spins that constitute the disordered ferrimagnetic shell, whose total moments block at (TB)=49 K and collectively freeze in a superspin-glass-type state at (Tg)=3 K. On the other hand, annealed nanoparticles are superparamagnetic at room temperature and behave as an exchange-coupled system below the blocking temperature (TB)=70 K, with enhanced coercivity HC(10K)∼14.6 kOe and exchange bias field HEB(10K)∼2.3 kOe, compared with the as-synthesized system where HC(10K)∼5.5 kOe and HEB(10K)∼0.8 kOe. Our results, interpreted using different models for thermally activated and surface relaxation processes, can help clarify the complex magnetic behavior of many core/shell and hollow nanoparticle systems.
Fil: Lavorato, Gabriel Carlos. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Winkler, Elin Lilian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Ghirri, Alberto. Consiglio Nazionale delle Ricerche; Italia
Fil: Lima, Enio Junior. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Peddis, Davide. Consiglio Nazionale delle Ricerche; Italia
Fil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
Fil: Fiorani, Dino. Consiglio Nazionale delle Ricerche; Italia
Fil: Agostinelli, Elisabetta. Consiglio Nazionale delle Ricerche; Italia
Fil: Rinaldi, Daniele. Universita Politecnica delle Marche via Brecce Bianche; Italia
Fil: Zysler, Roberto Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina
description Bimagnetic nanoparticles have been proposed for the design of new materials with controlled properties, which requires a comprehensive investigation of their magnetic behavior due to multiple effects arising from their complex structure. In this work we fabricated bimagnetic core/shell nanoparticles formed by an ∼3-nm antiferromagnetic (AFM) CoO core encapsulated within an ∼1.5-nm ferrimagnetic (FiM) Co0.5Ni0.5Fe2O4 shell, aiming at studying the enhancement of the magnetic anisotropy and the surface effects of a ferrimagnetic oxide shell. The magnetic properties of as-synthesized and annealed samples were analyzed by ac and dc magnetization measurements. The results indicate that the magnetic response of the as-synthesized particles is governed by the superparamagnetic behavior of the interacting nanoaggregates of spins that constitute the disordered ferrimagnetic shell, whose total moments block at (TB)=49 K and collectively freeze in a superspin-glass-type state at (Tg)=3 K. On the other hand, annealed nanoparticles are superparamagnetic at room temperature and behave as an exchange-coupled system below the blocking temperature (TB)=70 K, with enhanced coercivity HC(10K)∼14.6 kOe and exchange bias field HEB(10K)∼2.3 kOe, compared with the as-synthesized system where HC(10K)∼5.5 kOe and HEB(10K)∼0.8 kOe. Our results, interpreted using different models for thermally activated and surface relaxation processes, can help clarify the complex magnetic behavior of many core/shell and hollow nanoparticle systems.
publishDate 2016
dc.date.none.fl_str_mv 2016-08
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/126149
Lavorato, Gabriel Carlos; Winkler, Elin Lilian; Ghirri, Alberto; Lima, Enio Junior; Peddis, Davide; et al.; Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles; American Physical Society; Physical Review B; 94; 5; 8-2016; 544321-544329
2469-9969
CONICET Digital
CONICET
url http://hdl.handle.net/11336/126149
identifier_str_mv Lavorato, Gabriel Carlos; Winkler, Elin Lilian; Ghirri, Alberto; Lima, Enio Junior; Peddis, Davide; et al.; Exchange bias and surface effects in bimagnetic CoO-core/Co0.5Ni0.5Fe2 O4 -shell nanoparticles; American Physical Society; Physical Review B; 94; 5; 8-2016; 544321-544329
2469-9969
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.054432
info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.94.054432
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.13397

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