Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/29834 |
Resumo: | Manganese-Zinc ferrite nanoparticles have been the subject of increasing research due to their desired properties for a wide range of applications. These properties include nanometer particle size control, tunable magnetic properties, high saturation magnetization and low toxicity, providing these ferrites with the necessary requirements for cancer treatment via magnetic hyperthermia. During this research, powders of Mn-Zn ferrite were synthesized and characterized, aiming to optimize their structural and magnetic properties for further application in a ferrofluid. Samples with Mn1-xZnxFe2O4 (x=0; 0.5; 0.8; 1) compositions were synthesized via the sol-gel auto-combustion and hydrothermal methods. Synthesized powders were characterized by XRD, SQUID, SEM, TEM and magnetic induction heating techniques. The XRD diffractograms of hydrothermally produced samples presented spinel crystal structure with high single-phase percentage (>88%). Rietveld refinement and Williamson-Hall analysis revealed a decrease of lattice constant (8.50 to 8.46 Å) and crystallite size (61 to 11 nm) with increase of Zn/Mn ratio. TEM images reveals narrow particle size distributions and decrease of the mean particle size (41 to 7 nm) with the Zn/Mn ratio increase. SQUID results showed that the increase of Zn results in a decrease of saturation magnetization (79 to 19 emu/g) and remnant magnetization (5 to approximately 0 emu/g). More noticeably, the M(T) curves present a shift in the samples magnetic ordering temperature towards lower temperatures with the increase of Zn content, from ~556 (estimated) to ~284 K. The magnetic induction heating experiment also unveiled a decrease in the heating rate with the increase of Zn in ferrite. Nanocrystals of Mn-Zn ferrite produced by hydrothermal method present better crystallinity and magnetic properties than the sol-gel auto-combustion samples. The hydrothermally synthesized samples revealed dependence of its structural and magnetic properties with Mn/Zn ratio. The magnetic ordering temperature of these ferrites can be used as a self-controlled mechanism of heating, raising these ferrites to a class of smart materials. |
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Synthesis optimization of Zn-Mn ferrites for magnetic fluid applicationsSelf-Regulated HeatingMn-Zn ferriteSol-gel auto-combustion methodHydrothermal methodCurie temperatureMagnetic ordering temperatureManganese-Zinc ferrite nanoparticles have been the subject of increasing research due to their desired properties for a wide range of applications. These properties include nanometer particle size control, tunable magnetic properties, high saturation magnetization and low toxicity, providing these ferrites with the necessary requirements for cancer treatment via magnetic hyperthermia. During this research, powders of Mn-Zn ferrite were synthesized and characterized, aiming to optimize their structural and magnetic properties for further application in a ferrofluid. Samples with Mn1-xZnxFe2O4 (x=0; 0.5; 0.8; 1) compositions were synthesized via the sol-gel auto-combustion and hydrothermal methods. Synthesized powders were characterized by XRD, SQUID, SEM, TEM and magnetic induction heating techniques. The XRD diffractograms of hydrothermally produced samples presented spinel crystal structure with high single-phase percentage (>88%). Rietveld refinement and Williamson-Hall analysis revealed a decrease of lattice constant (8.50 to 8.46 Å) and crystallite size (61 to 11 nm) with increase of Zn/Mn ratio. TEM images reveals narrow particle size distributions and decrease of the mean particle size (41 to 7 nm) with the Zn/Mn ratio increase. SQUID results showed that the increase of Zn results in a decrease of saturation magnetization (79 to 19 emu/g) and remnant magnetization (5 to approximately 0 emu/g). More noticeably, the M(T) curves present a shift in the samples magnetic ordering temperature towards lower temperatures with the increase of Zn content, from ~556 (estimated) to ~284 K. The magnetic induction heating experiment also unveiled a decrease in the heating rate with the increase of Zn in ferrite. Nanocrystals of Mn-Zn ferrite produced by hydrothermal method present better crystallinity and magnetic properties than the sol-gel auto-combustion samples. The hydrothermally synthesized samples revealed dependence of its structural and magnetic properties with Mn/Zn ratio. The magnetic ordering temperature of these ferrites can be used as a self-controlled mechanism of heating, raising these ferrites to a class of smart materials.Nanopartículas de ferrite Manganês-Zinco são cada vez mais investigadas pelas suas propriedades desejadas para uma vasta gama de aplicações. Essas propriedades incluem controlo nanométrico de tamanho de partícula, propriedades magnéticas ajustáveis, elevada magnetização de saturação e baixa toxicidade, providenciando estas ferrites com os requerimentos necessários para tratamento de cancro por hipertermia magnética. Durante esta investigação, foram sintetizados e caracterizados pós de ferrite de Mn-Zn, visando otimizar as suas propriedades estruturais e magnéticas para futura aplicação num ferrofluido. Amostras de Mn1-xZnxFe2O4 (x=0; 0.5; 0.8; 1) foram sintetizadas pelos métodos de autocombustão de sol-gel e pelo método hidrotermal. Os pós sintetizados foram caracterizados por XRD, SQUID, SEM, TEM e aquecimento por indução magnética. Os difratogramas de XRD das amostras produzidas pelo método de hidrotermal apresentam a estrutura cristalina de espinela com elevada percentagem de fase-única (>88%). O refinamento de Rietveld e a análise de Williamson-Hall revelam decréscimos no parâmetro de rede (8.50 até 8.46 Å) e no tamanho médio de cristalite (61 até 11 nm) com o aumento da razão Zn/Mn. As imagens de TEM revelam uma estreita distribuição de tamanhos e um decréscimo do tamanho médio de partícula (41 até 7 nm) com o aumento da razão Zn/Mn. Os resultados de SQUID mostram que o aumento de Zn resulta num decréscimo de magnetização de saturação (79 até 19 emu/g) e de magnetização remanente (5 até aproximadamente 0 emu/g). Notoriamente, as curvas M(T) revelaram um desvio na temperatura de ordenamento magnético para mais baixas temperaturas com o aumento de Zn, de ~556 (estimado) até ~284 K. A experiência de aquecimento por indução também revelou um decréscimo na taxa de aquecimento com o aumento de Zn na ferrite. Nano-cristais de ferrite de Mn-Zn produzidos pelo método hidrotermal apresentam melhor cristalinidade e propriedades magnéticas que as amostras de autocombustão de sol-gel. As amostras sintetizadas pelo método hidrotermal revelam dependência das suas propriedades estruturais e magnéticas com a razão Zn/Mn. A temperatura de ordenamento magnético destas ferrites pode ser usada como um mecanismo de aquecimento autorregulado, elevando estas ferrites para uma classe de materiais inteligentes.2020-11-18T16:08:43Z2019-11-01T00:00:00Z2019-11info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10773/29834engHorta, André Filipe Castanheirainfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-05-06T04:28:42Zoai:ria.ua.pt:10773/29834Portal AgregadorONGhttps://www.rcaap.pt/oai/openairemluisa.alvim@gmail.comopendoar:71602024-05-06T04:28:42Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
title |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
spellingShingle |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications Horta, André Filipe Castanheira Self-Regulated Heating Mn-Zn ferrite Sol-gel auto-combustion method Hydrothermal method Curie temperature Magnetic ordering temperature |
title_short |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
title_full |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
title_fullStr |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
title_full_unstemmed |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
title_sort |
Synthesis optimization of Zn-Mn ferrites for magnetic fluid applications |
author |
Horta, André Filipe Castanheira |
author_facet |
Horta, André Filipe Castanheira |
author_role |
author |
dc.contributor.author.fl_str_mv |
Horta, André Filipe Castanheira |
dc.subject.por.fl_str_mv |
Self-Regulated Heating Mn-Zn ferrite Sol-gel auto-combustion method Hydrothermal method Curie temperature Magnetic ordering temperature |
topic |
Self-Regulated Heating Mn-Zn ferrite Sol-gel auto-combustion method Hydrothermal method Curie temperature Magnetic ordering temperature |
description |
Manganese-Zinc ferrite nanoparticles have been the subject of increasing research due to their desired properties for a wide range of applications. These properties include nanometer particle size control, tunable magnetic properties, high saturation magnetization and low toxicity, providing these ferrites with the necessary requirements for cancer treatment via magnetic hyperthermia. During this research, powders of Mn-Zn ferrite were synthesized and characterized, aiming to optimize their structural and magnetic properties for further application in a ferrofluid. Samples with Mn1-xZnxFe2O4 (x=0; 0.5; 0.8; 1) compositions were synthesized via the sol-gel auto-combustion and hydrothermal methods. Synthesized powders were characterized by XRD, SQUID, SEM, TEM and magnetic induction heating techniques. The XRD diffractograms of hydrothermally produced samples presented spinel crystal structure with high single-phase percentage (>88%). Rietveld refinement and Williamson-Hall analysis revealed a decrease of lattice constant (8.50 to 8.46 Å) and crystallite size (61 to 11 nm) with increase of Zn/Mn ratio. TEM images reveals narrow particle size distributions and decrease of the mean particle size (41 to 7 nm) with the Zn/Mn ratio increase. SQUID results showed that the increase of Zn results in a decrease of saturation magnetization (79 to 19 emu/g) and remnant magnetization (5 to approximately 0 emu/g). More noticeably, the M(T) curves present a shift in the samples magnetic ordering temperature towards lower temperatures with the increase of Zn content, from ~556 (estimated) to ~284 K. The magnetic induction heating experiment also unveiled a decrease in the heating rate with the increase of Zn in ferrite. Nanocrystals of Mn-Zn ferrite produced by hydrothermal method present better crystallinity and magnetic properties than the sol-gel auto-combustion samples. The hydrothermally synthesized samples revealed dependence of its structural and magnetic properties with Mn/Zn ratio. The magnetic ordering temperature of these ferrites can be used as a self-controlled mechanism of heating, raising these ferrites to a class of smart materials. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-11-01T00:00:00Z 2019-11 2020-11-18T16:08:43Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/29834 |
url |
http://hdl.handle.net/10773/29834 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
mluisa.alvim@gmail.com |
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1817543760844685312 |