Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário
Ano de defesa: | 2008 |
---|---|
Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Tese |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal de São Carlos
|
Programa de Pós-Graduação: |
Programa de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEM
|
Departamento: |
Não Informado pela instituição
|
País: |
BR
|
Palavras-chave em Português: | |
Área do conhecimento CNPq: | |
Link de acesso: | https://repositorio.ufscar.br/handle/ufscar/654 |
Resumo: | In this work Cobalt and Titanium doped Barium hexaferrites were synthesized by the ceramic method in order to study their use as electromagnetic absorbing materials in high frequencies. The dopants were used individually (Ti and Co) and with both simultaneously (CT). Ceramic characteristics and magnetic properties of calcined powders, as well as of their pellets sintered in electric and microwave furnaces were evaluated. For the high frequency permeability measurements, hexaferrites ring-shaped sintered and ring-shaped composites with the hexaferrite powders and epoxi resin were produced. Barium hexaferrite powder (BaM) presented 3.45 kOe of coercivity and the same synthesizing conditions were used in all hexaferrites with dopant atomic fractions of 0,2; 0,4; 0,6; 0,8; and 1,0. In Ti hexaferrites (BaFe12-xTixO19) microstructures there were BaFe2O4, Fe2O3 and Ba3Fe10TiO20 phases and they presented coercivities between 1,53 and 1,04 kOe. Co hexaferrites (BaFe12- xCoxO19) microstructures showed W, Y and Z hexaferrites types phases, with coercivities between 0,70 and 0,21 kOe. In CT hexaferrites (BaFe12-2xCoxTixO19) it was presented CoFe2O4 phase, with coercivities between 0,09 and 1,06 kOe was presented. Most of the pellets sintered in microwave furnace had apparent densities close to those of the pellets sintered in electric furnace and their coercivities were higher or equal. The grains heterogeneity increased with dopant quantities and the Ti microstructures presented more quantity of M type hexaferrites in comparison to other samples. The ring-shaped sintered samples of BaM, Ti and CT hexaferrites showed ferrimagnetic ressonance peaks in 110 MHz and 780 GHz. In Co hexaferrites the presence of hexaferrites different from M type contributed to the different tangent loss in comparison to other hexaferrites. The tangent loss of composites showed the same peaks observed in the ring-shaped sintered samples but with smaller intensities. These composites showed absorption loss up to 20 dB in 12 GHz too. |
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Yasuda, Márcio TsuyoshiMorelli, Márcio Raymundohttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4780873E7http://lattes.cnpq.br/71757250209463752016-06-02T19:09:59Z2008-05-082016-06-02T19:09:59Z2008-02-22YASUDA, Márcio Tsuyoshi. A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite. 2008. 265 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008.https://repositorio.ufscar.br/handle/ufscar/654In this work Cobalt and Titanium doped Barium hexaferrites were synthesized by the ceramic method in order to study their use as electromagnetic absorbing materials in high frequencies. The dopants were used individually (Ti and Co) and with both simultaneously (CT). Ceramic characteristics and magnetic properties of calcined powders, as well as of their pellets sintered in electric and microwave furnaces were evaluated. For the high frequency permeability measurements, hexaferrites ring-shaped sintered and ring-shaped composites with the hexaferrite powders and epoxi resin were produced. Barium hexaferrite powder (BaM) presented 3.45 kOe of coercivity and the same synthesizing conditions were used in all hexaferrites with dopant atomic fractions of 0,2; 0,4; 0,6; 0,8; and 1,0. In Ti hexaferrites (BaFe12-xTixO19) microstructures there were BaFe2O4, Fe2O3 and Ba3Fe10TiO20 phases and they presented coercivities between 1,53 and 1,04 kOe. Co hexaferrites (BaFe12- xCoxO19) microstructures showed W, Y and Z hexaferrites types phases, with coercivities between 0,70 and 0,21 kOe. In CT hexaferrites (BaFe12-2xCoxTixO19) it was presented CoFe2O4 phase, with coercivities between 0,09 and 1,06 kOe was presented. Most of the pellets sintered in microwave furnace had apparent densities close to those of the pellets sintered in electric furnace and their coercivities were higher or equal. The grains heterogeneity increased with dopant quantities and the Ti microstructures presented more quantity of M type hexaferrites in comparison to other samples. The ring-shaped sintered samples of BaM, Ti and CT hexaferrites showed ferrimagnetic ressonance peaks in 110 MHz and 780 GHz. In Co hexaferrites the presence of hexaferrites different from M type contributed to the different tangent loss in comparison to other hexaferrites. The tangent loss of composites showed the same peaks observed in the ring-shaped sintered samples but with smaller intensities. These composites showed absorption loss up to 20 dB in 12 GHz too.A síntese por mistura de óxidos foi utilizada na produção de hexaferritas de bário dopadas substitucionalmente com íons titânio (Ti), cobalto (Co), e titânio e cobalto simultaneamente (CT). Estas hexaferritas foram processadas a fim de se avaliar as suas propriedades magnéticas e absorvedoras de radiação eletromagnética, na forma de pó e em compactos sinterizados. Compósitos entre estes pós e resina epóxi foram conformados em toróides para o estudo de permeabilidade em altas freqüências, assim como de toróides de hexaferritas sinterizadas. O pó de hexaferrita de bário (BaM) foi obtido com coercividade de 3,45 kOe e as mesmas condições de sua síntese foram utilizadas para os diferentes tipos de dopagem nas frações atômicas de 0,2; 0,4; 0,6; 0,8; e 1,0. Pós de hexaferritas Ti (BaFe12-xTixO19) apresentaram as fases secundárias BaFe2O4, Fe2O3 e Ba3Fe10TiO20, e coercividades entre 1,53 e 1,04 kOe. Pós de hexaferritas Co (BaFe12-xCoxO19) apresentaram as fases hexaferritas do tipo W, Y e Z, e coercividades entre 0,70 e 0,21 kOe. Pós de hexaferritas CT (BaFe12-2xCoxTixO19) apresentaram a fase secundária CoFe2O4 e coercividades entre 0,09 e 1,06 kOe. Amostras sinterizadas por microondas atingiram densidades aparentes próximas às sinterizadas em forno elétrico, microestruturas mais homogêneas e coercividades iguais ou superiores. A heterogeneidade de grãos aumentou com o teor de dopante, onde as composições Ti apresentaram maior quantidade da fase hexaferrita do tipo M. Os toróides BaM, Ti e CT apresentaram dois picos de ressonância ferrimagnética, em 110 MHz e em 780 GHz. Nos toróides Co as fases hexaferritas distintas do tipo M contribuíram para tangentes de perda diferentes dos demais toróides. As tangentes de perda dos compósitos apresentaram os mesmos comportamentos observados nos respectivos toróides sinterizados, porém com intensidades inferiores, demonstrando suas menores capacidades absorvedoras. Todos os compósitos se mostraram eficientes na absorção de radiação eletromagnética em aproximadamente 12 GHz, sendo esta de até 20 dB.Universidade Federal de Sao Carlosapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEMUFSCarBRPropriedades magnéticasMicroondasHexaferritasRadiação eletromagnéticaENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICAEstudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bárioA study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferriteinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL1750.pdfapplication/pdf18500069https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/654/1/1750.pdf695f0dd214921b76cc3d4363f185f69aMD51THUMBNAIL1750.pdf.jpg1750.pdf.jpgIM Thumbnailimage/jpeg6663https://{{ getenv "DSPACE_HOST" "repositorio.ufscar.br" }}/bitstream/ufscar/654/2/1750.pdf.jpgbe26aaa31e4ef42d2de3a94843e21c0eMD52ufscar/6542019-11-12 13:49:37.219oai:repositorio.ufscar.br:ufscar/654Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-05-25T12:43:33.364059Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
dc.title.alternative.eng.fl_str_mv |
A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite |
title |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
spellingShingle |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário Yasuda, Márcio Tsuyoshi Propriedades magnéticas Microondas Hexaferritas Radiação eletromagnética ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
title_short |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
title_full |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
title_fullStr |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
title_full_unstemmed |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
title_sort |
Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário |
author |
Yasuda, Márcio Tsuyoshi |
author_facet |
Yasuda, Márcio Tsuyoshi |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/7175725020946375 |
dc.contributor.author.fl_str_mv |
Yasuda, Márcio Tsuyoshi |
dc.contributor.advisor1.fl_str_mv |
Morelli, Márcio Raymundo |
dc.contributor.advisor1Lattes.fl_str_mv |
http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4780873E7 |
contributor_str_mv |
Morelli, Márcio Raymundo |
dc.subject.por.fl_str_mv |
Propriedades magnéticas Microondas Hexaferritas Radiação eletromagnética |
topic |
Propriedades magnéticas Microondas Hexaferritas Radiação eletromagnética ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
description |
In this work Cobalt and Titanium doped Barium hexaferrites were synthesized by the ceramic method in order to study their use as electromagnetic absorbing materials in high frequencies. The dopants were used individually (Ti and Co) and with both simultaneously (CT). Ceramic characteristics and magnetic properties of calcined powders, as well as of their pellets sintered in electric and microwave furnaces were evaluated. For the high frequency permeability measurements, hexaferrites ring-shaped sintered and ring-shaped composites with the hexaferrite powders and epoxi resin were produced. Barium hexaferrite powder (BaM) presented 3.45 kOe of coercivity and the same synthesizing conditions were used in all hexaferrites with dopant atomic fractions of 0,2; 0,4; 0,6; 0,8; and 1,0. In Ti hexaferrites (BaFe12-xTixO19) microstructures there were BaFe2O4, Fe2O3 and Ba3Fe10TiO20 phases and they presented coercivities between 1,53 and 1,04 kOe. Co hexaferrites (BaFe12- xCoxO19) microstructures showed W, Y and Z hexaferrites types phases, with coercivities between 0,70 and 0,21 kOe. In CT hexaferrites (BaFe12-2xCoxTixO19) it was presented CoFe2O4 phase, with coercivities between 0,09 and 1,06 kOe was presented. Most of the pellets sintered in microwave furnace had apparent densities close to those of the pellets sintered in electric furnace and their coercivities were higher or equal. The grains heterogeneity increased with dopant quantities and the Ti microstructures presented more quantity of M type hexaferrites in comparison to other samples. The ring-shaped sintered samples of BaM, Ti and CT hexaferrites showed ferrimagnetic ressonance peaks in 110 MHz and 780 GHz. In Co hexaferrites the presence of hexaferrites different from M type contributed to the different tangent loss in comparison to other hexaferrites. The tangent loss of composites showed the same peaks observed in the ring-shaped sintered samples but with smaller intensities. These composites showed absorption loss up to 20 dB in 12 GHz too. |
publishDate |
2008 |
dc.date.available.fl_str_mv |
2008-05-08 2016-06-02T19:09:59Z |
dc.date.issued.fl_str_mv |
2008-02-22 |
dc.date.accessioned.fl_str_mv |
2016-06-02T19:09:59Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
YASUDA, Márcio Tsuyoshi. A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite. 2008. 265 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/654 |
identifier_str_mv |
YASUDA, Márcio Tsuyoshi. A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite. 2008. 265 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008. |
url |
https://repositorio.ufscar.br/handle/ufscar/654 |
dc.language.iso.fl_str_mv |
por |
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por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
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openAccess |
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dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEM |
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UFSCar |
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BR |
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Universidade Federal de São Carlos |
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