Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite

Bibliographic Details
Main Author: Martinelli, Antonio Eduardo
Publication Date: 2019
Other Authors: Gurgel, Ana Lúcia, Conceição, Ozivam Lopes de Aquino, Xavier Jr, Milton Moraes, Torres, Marco Antonio Morales, Melo, Dulce Maria de Araújo
Format: Article
Language: eng
Source: Repositório Institucional da UFRN
Download full: https://repositorio.ufrn.br/handle/123456789/31583
Summary: Cobalt ferrite is an important magnetic material due to its high saturation magnetization and high energy product BH. CoFe2O4 nanoparticles can be synthesized by a variety of methods that often demand long synthesis times. Using the microwave-assisted hydrothermal method, single-phase CoFe2O4 with controlled crystallite size was rapidly obtained. The effect of a preheating step and mineralizing agent, i.e., NH4OH and KOH, was investigated. Exposure to microwave radiation ranged from 0.5 to 2 h. The formation of CoFe2O4 was confirmed by X-ray diffraction. The average crystallite size of CoFe2O4 nanoparticles was estimated between 5.2 nm and 21.3 nm by Rietveld refinement. The crystallite size depended on the preheating step and mineralizing agent used. Transmission electron microscopy images revealed that CoFe2O4 nanoparticles were nearly spherical when prepared with NH4OH but cubic and spherical when prepared with KOH. Both, hysteresis curves and Mossbauer spectra at room temperature, € showed superparamagnetic behavior for samples with the smaller crystallite size. Samples with larger crystallites consisted of blocked particles and depicted an increase in the MR/MHmax ratio and coercive field, Hc. Distinct magnetic properties resulting from variations in the synthesis parameters yield different applications for nanostructured CoFe2O4
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spelling Martinelli, Antonio EduardoGurgel, Ana LúciaConceição, Ozivam Lopes de AquinoXavier Jr, Milton MoraesTorres, Marco Antonio MoralesMelo, Dulce Maria de Araújo2021-02-22T13:36:08Z2021-02-22T13:36:08Z2019-08GURGEL, Ana Lúcia; MARTINELLI, Antonio Eduardo; CONCEIÇÃO, Ozivam Lopes de Aquino; XAVIER, Milton Moraes; TORRES, Marco Antonio Morales; MELO, Dulce Maria de Araújo. Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite. Journal Of Alloys And Compounds, [S.L.], v. 799, p. 36-42, ago. 2019. Elsevier BV. http://dx.doi.org/10.1016/j.jallcom.2019.05.309. Disponível em: https://www.sciencedirect.com/science/article/abs/pii/S0925838819319978?via%3Dihub. Acesso em: 05 jan. 2021.0925-8388https://repositorio.ufrn.br/handle/123456789/3158310.1016/j.jallcom.2019.05.309Elsevier BVAttribution 3.0 Brazilhttp://creativecommons.org/licenses/by/3.0/br/info:eu-repo/semantics/openAccessTransition metal alloys and compoundsNanostructured materialsChemical synthesisMagnetic measurementsMossbauer spectroscopyMicrowave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferriteinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleCobalt ferrite is an important magnetic material due to its high saturation magnetization and high energy product BH. CoFe2O4 nanoparticles can be synthesized by a variety of methods that often demand long synthesis times. Using the microwave-assisted hydrothermal method, single-phase CoFe2O4 with controlled crystallite size was rapidly obtained. The effect of a preheating step and mineralizing agent, i.e., NH4OH and KOH, was investigated. Exposure to microwave radiation ranged from 0.5 to 2 h. The formation of CoFe2O4 was confirmed by X-ray diffraction. The average crystallite size of CoFe2O4 nanoparticles was estimated between 5.2 nm and 21.3 nm by Rietveld refinement. The crystallite size depended on the preheating step and mineralizing agent used. Transmission electron microscopy images revealed that CoFe2O4 nanoparticles were nearly spherical when prepared with NH4OH but cubic and spherical when prepared with KOH. Both, hysteresis curves and Mossbauer spectra at room temperature, € showed superparamagnetic behavior for samples with the smaller crystallite size. Samples with larger crystallites consisted of blocked particles and depicted an increase in the MR/MHmax ratio and coercive field, Hc. Distinct magnetic properties resulting from variations in the synthesis parameters yield different applications for nanostructured CoFe2O4engreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdfMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdfapplication/pdf3721681https://repositorio.ufrn.br/bitstream/123456789/31583/1/MicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf42dc31fc634491d526f63d9a3126b754MD51CC-LICENSElicense_rdflicense_rdfapplication/rdf+xml; charset=utf-8914https://repositorio.ufrn.br/bitstream/123456789/31583/2/license_rdf4d2950bda3d176f570a9f8b328dfbbefMD52LICENSElicense.txtlicense.txttext/plain; charset=utf-81484https://repositorio.ufrn.br/bitstream/123456789/31583/3/license.txte9597aa2854d128fd968be5edc8a28d9MD53TEXTMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.txtMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.txtExtracted texttext/plain25928https://repositorio.ufrn.br/bitstream/123456789/31583/4/MicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.txtba969569e8d0f5fd86196edd3a9d06f5MD54THUMBNAILMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.jpgMicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.jpgGenerated Thumbnailimage/jpeg1704https://repositorio.ufrn.br/bitstream/123456789/31583/5/MicrowaveAssistedHydrothermal_MARTINELLI_2019.pdf.jpg77e0930500c698406a305989a8f86c85MD55123456789/315832021-02-28 05:46:22.448oai:https://repositorio.ufrn.br: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Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2021-02-28T08:46:22Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false
dc.title.pt_BR.fl_str_mv Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
title Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
spellingShingle Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
Martinelli, Antonio Eduardo
Transition metal alloys and compounds
Nanostructured materials
Chemical synthesis
Magnetic measurements
Mossbauer spectroscopy
title_short Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
title_full Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
title_fullStr Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
title_full_unstemmed Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
title_sort Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite
author Martinelli, Antonio Eduardo
author_facet Martinelli, Antonio Eduardo
Gurgel, Ana Lúcia
Conceição, Ozivam Lopes de Aquino
Xavier Jr, Milton Moraes
Torres, Marco Antonio Morales
Melo, Dulce Maria de Araújo
author_role author
author2 Gurgel, Ana Lúcia
Conceição, Ozivam Lopes de Aquino
Xavier Jr, Milton Moraes
Torres, Marco Antonio Morales
Melo, Dulce Maria de Araújo
author2_role author
author
author
author
author
dc.contributor.author.fl_str_mv Martinelli, Antonio Eduardo
Gurgel, Ana Lúcia
Conceição, Ozivam Lopes de Aquino
Xavier Jr, Milton Moraes
Torres, Marco Antonio Morales
Melo, Dulce Maria de Araújo
dc.subject.por.fl_str_mv Transition metal alloys and compounds
Nanostructured materials
Chemical synthesis
Magnetic measurements
Mossbauer spectroscopy
topic Transition metal alloys and compounds
Nanostructured materials
Chemical synthesis
Magnetic measurements
Mossbauer spectroscopy
description Cobalt ferrite is an important magnetic material due to its high saturation magnetization and high energy product BH. CoFe2O4 nanoparticles can be synthesized by a variety of methods that often demand long synthesis times. Using the microwave-assisted hydrothermal method, single-phase CoFe2O4 with controlled crystallite size was rapidly obtained. The effect of a preheating step and mineralizing agent, i.e., NH4OH and KOH, was investigated. Exposure to microwave radiation ranged from 0.5 to 2 h. The formation of CoFe2O4 was confirmed by X-ray diffraction. The average crystallite size of CoFe2O4 nanoparticles was estimated between 5.2 nm and 21.3 nm by Rietveld refinement. The crystallite size depended on the preheating step and mineralizing agent used. Transmission electron microscopy images revealed that CoFe2O4 nanoparticles were nearly spherical when prepared with NH4OH but cubic and spherical when prepared with KOH. Both, hysteresis curves and Mossbauer spectra at room temperature, € showed superparamagnetic behavior for samples with the smaller crystallite size. Samples with larger crystallites consisted of blocked particles and depicted an increase in the MR/MHmax ratio and coercive field, Hc. Distinct magnetic properties resulting from variations in the synthesis parameters yield different applications for nanostructured CoFe2O4
publishDate 2019
dc.date.issued.fl_str_mv 2019-08
dc.date.accessioned.fl_str_mv 2021-02-22T13:36:08Z
dc.date.available.fl_str_mv 2021-02-22T13:36:08Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.citation.fl_str_mv GURGEL, Ana Lúcia; MARTINELLI, Antonio Eduardo; CONCEIÇÃO, Ozivam Lopes de Aquino; XAVIER, Milton Moraes; TORRES, Marco Antonio Morales; MELO, Dulce Maria de Araújo. Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite. Journal Of Alloys And Compounds, [S.L.], v. 799, p. 36-42, ago. 2019. Elsevier BV. http://dx.doi.org/10.1016/j.jallcom.2019.05.309. Disponível em: https://www.sciencedirect.com/science/article/abs/pii/S0925838819319978?via%3Dihub. Acesso em: 05 jan. 2021.
dc.identifier.uri.fl_str_mv https://repositorio.ufrn.br/handle/123456789/31583
dc.identifier.issn.none.fl_str_mv 0925-8388
dc.identifier.doi.none.fl_str_mv 10.1016/j.jallcom.2019.05.309
identifier_str_mv GURGEL, Ana Lúcia; MARTINELLI, Antonio Eduardo; CONCEIÇÃO, Ozivam Lopes de Aquino; XAVIER, Milton Moraes; TORRES, Marco Antonio Morales; MELO, Dulce Maria de Araújo. Microwave-assisted hydrothermal synthesis and magnetic properties of nanostructured cobalt ferrite. Journal Of Alloys And Compounds, [S.L.], v. 799, p. 36-42, ago. 2019. Elsevier BV. http://dx.doi.org/10.1016/j.jallcom.2019.05.309. Disponível em: https://www.sciencedirect.com/science/article/abs/pii/S0925838819319978?via%3Dihub. Acesso em: 05 jan. 2021.
0925-8388
10.1016/j.jallcom.2019.05.309
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