PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er).
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da UFMA |
Texto Completo: | https://tedebc.ufma.br/jspui/handle/tede/tede/2965 |
Resumo: | Structural, magnetic and magnetocaloric properties of the RNiGe3 (R = Pr, Nd, Eu, Dy, Ho and Er) compounds were studied. The samples were synthesized by arc melting technique under argon atmosphere. X-ray diffraction (XRD) measurements and analysis by using the Rietveld method confirm the desired crystallographic phase for all studied samples. Magnetization data shows antiferromagnetic ordering for RNiGe3 compounds, with Néel temperature (TN) around 21 K, 12.5 K, 14 K, 21 K, 9 K and 6 K for R = Pr, Nd, Eu, Dy, Ho and Er, respectively. For T<TN, the compounds NdNiGe3 and EuNiGe3 present an additional transition around 6.1 K and 5 K, respectively, while PrNiGe3 presents two additional transitions around 18.5 and 15.5 K. External magnetic field application induces metamagnetic phase transitions from antiferromagnetic to ferromagnetic state. However, the observed values of the magnetic moments in high magnetic field (H= 60 and 90 kOe) and low temperatures (T = 2 K) are reduced compared to the respective free ions. The metamagnetic critical magnetic field (HC) occurs around 16 kOe, 17.3 kOe, 26.5 kOe, 10.5 kOe and 9.5 kOe, for R = Pr, Nd, Dy, Ho and Er, respectively, and around 20 and 28 kOe for R=Eu. Magnetocaloric effect (MCE) of studies compounds was evaluated by means of the isothermal magnetic entropy change (-ΔSM), in which a broad peak in -ΔSM curve associated with the magnetic transition was observed. In addition, negative MCE was observed for all samples (in ΔH < HC) due to antiferromagnetic ordering. Among the studies compounds, the highest value of -ΔSM was observed for HoNiGe3. The maximum values of -ΔSM (−𝛥𝑆𝑀𝑚𝑎𝑥) and relative cooling power (RCP) observed for RNiGe3 series were respectively, 6.1 J/kg.K and 72.9 J/kg, 4.2 J/kg.K and 68.2 J/kg, 7.5 J/kg.K and 113.6 J/kg, 5.0 J/kg.K and 106 J/kg, 16.7 J/kg.K and 308.5 J/kg, and 11.3 J/kg.K and 214.7 J/kg, for R = Pr, Nd, Eu, Dy, Ho and Er, in ΔH = 50 kOe. These values are comparable to those reported in the literature for other magnetocaloric compounds, in the same temperature range. The obtained results indicate that the RNiGe3 compounds presented interesting magnetocaloric properties for application in magnetic refrigeration at cryogenic temperatures. |
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SILVA, Luzeli Moreira da438.074.022-68http://lattes.cnpq.br/5651616479126344SILVA, Luzeli Moreira da438.074.022-68http://lattes.cnpq.br/5651616479126344SANTOS, Adenilson Oliveira doshttp://lattes.cnpq.br/7760219759813661SILVA, Leonardo de Sousa056.750.023-32http://lattes.cnpq.br/3515712441056475ARAÚJO, Ronaldo Andrade de2020-01-08T13:50:49Z2019-07-08ARAÚJO, Ronaldo Andrade de. Propriedades magnéticas e magnetocalóricas do sistema RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er).. 2019. 83 f. Dissertação( Programa de Pós-Graduação em Ciência dos Materiais/CCSST) - Universidade Federal do Maranhão, Imperatriz, 2019.https://tedebc.ufma.br/jspui/handle/tede/tede/2965Structural, magnetic and magnetocaloric properties of the RNiGe3 (R = Pr, Nd, Eu, Dy, Ho and Er) compounds were studied. The samples were synthesized by arc melting technique under argon atmosphere. X-ray diffraction (XRD) measurements and analysis by using the Rietveld method confirm the desired crystallographic phase for all studied samples. Magnetization data shows antiferromagnetic ordering for RNiGe3 compounds, with Néel temperature (TN) around 21 K, 12.5 K, 14 K, 21 K, 9 K and 6 K for R = Pr, Nd, Eu, Dy, Ho and Er, respectively. For T<TN, the compounds NdNiGe3 and EuNiGe3 present an additional transition around 6.1 K and 5 K, respectively, while PrNiGe3 presents two additional transitions around 18.5 and 15.5 K. External magnetic field application induces metamagnetic phase transitions from antiferromagnetic to ferromagnetic state. However, the observed values of the magnetic moments in high magnetic field (H= 60 and 90 kOe) and low temperatures (T = 2 K) are reduced compared to the respective free ions. The metamagnetic critical magnetic field (HC) occurs around 16 kOe, 17.3 kOe, 26.5 kOe, 10.5 kOe and 9.5 kOe, for R = Pr, Nd, Dy, Ho and Er, respectively, and around 20 and 28 kOe for R=Eu. Magnetocaloric effect (MCE) of studies compounds was evaluated by means of the isothermal magnetic entropy change (-ΔSM), in which a broad peak in -ΔSM curve associated with the magnetic transition was observed. In addition, negative MCE was observed for all samples (in ΔH < HC) due to antiferromagnetic ordering. Among the studies compounds, the highest value of -ΔSM was observed for HoNiGe3. The maximum values of -ΔSM (−𝛥𝑆𝑀𝑚𝑎𝑥) and relative cooling power (RCP) observed for RNiGe3 series were respectively, 6.1 J/kg.K and 72.9 J/kg, 4.2 J/kg.K and 68.2 J/kg, 7.5 J/kg.K and 113.6 J/kg, 5.0 J/kg.K and 106 J/kg, 16.7 J/kg.K and 308.5 J/kg, and 11.3 J/kg.K and 214.7 J/kg, for R = Pr, Nd, Eu, Dy, Ho and Er, in ΔH = 50 kOe. These values are comparable to those reported in the literature for other magnetocaloric compounds, in the same temperature range. The obtained results indicate that the RNiGe3 compounds presented interesting magnetocaloric properties for application in magnetic refrigeration at cryogenic temperatures.Neste trabalho foi realizado um estudo das propriedades estruturais, magnéticas e magnetocalóricas dos compostos da série RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). As amostras foram sintetizadas via fusão em forno à arco voltaico, sob atmosfera de argônio. Medidas de difração de Raios X e a análise pelo método de Rietveld confirmaram que todas as amostras apresentaram a fase cristalográfica desejada. Medidas de magnetização mostraram que esses compostos apresentam ordenamento antiferromagnético com temperatura de Néel (TN) em torno de 21 K, 12,5 K, 14 K, 21 K, 9 K e 6 K, para R = Pr, Nd, Eu, Dy, Ho e Er, respectivamente. Uma transição adicional em T = 6,1 K e 5 K, foi observada para R = Nd e Eu, respectivamente. Já o composto PrNiGe3 apresenta duas transições adicionais (18,5 K, 15,5 K) em T < TN. A aplicação de campo magnético externo induz transição metamagnética em todos os compostos em estudo, porém em altos campos magnéticos os valores dos momentos magnéticos em T = 2 K estão reduzidos comparando-se com os respectivos íons livres. O campo crítico da transição metamagnética (HC) ocorre em 16 kOe, 17,3 kOe, 26,5 kOe, 10,5 kOe e 9,5 kOe, para R = Pr, Nd, Dy, Ho e Er, respectivamente e de 20 e 28 kOe para R=Eu. A magnitude do efeito magnetocalórico (EMC) dos compostos foi avaliada por meio da variação isotérmica da entropia magnética (-ΔSM), tendo sido caracterizado por um pico alargado nas curvas de -ΔSM associado com a transição magnética. EMC negativo foi observado para todas as amostras (em ΔH < HC), devido ao ordenamento antiferromagnético. O composto HoNiGe3 mostrou variação de entropia isotérmica mais intensa quando comparada aos outros compostos deste estudo. Os valores máximos da -ΔSM (−𝛥𝑆𝑀𝑚𝑎𝑥) e poder de resfriamento relativo (RCP) obtidos para a série RNiGe3 foram, respectivamente, 6,1 J/kg.K e 72,9 J/kg, 4,2 J/kg.K e 68,2 J/kg, 7,5 J/kg.K e 113,6 J/kg, 5,0 J/kg.K e 106 J/kg, 16,7 J/kg.K e 308,5 J/kg, e 11,3 J/kg.K e 214,7 J/kg, para R = Pr, Nd, Eu, Dy, Ho e Er, em ΔH = 50 kOe. Estes valores são comparáveis aos relatados na literatura para outros compostos magnetocalóricos, na mesma faixa de temperatura. Os resultados obtidos indicam que os compostos RNiGe3 apresentam propriedades magnetocalóricas interessantes para aplicação na refrigeração magnética em temperaturas criogênicas.Submitted by Maria Aparecida (cidazen@gmail.com) on 2020-01-08T13:50:49Z No. of bitstreams: 1 Ronaldo A. de Araújo.pdf: 6235294 bytes, checksum: c28695f18e10477daefcb82d5b93b26e (MD5)Made available in DSpace on 2020-01-08T13:50:49Z (GMT). No. of bitstreams: 1 Ronaldo A. de Araújo.pdf: 6235294 bytes, checksum: c28695f18e10477daefcb82d5b93b26e (MD5) Previous issue date: 2019-07-08CNPqFAPEMACAPESapplication/pdfporUniversidade Federal do MaranhãoPROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIA DOS MATERIAIS/CCSSTUFMABrasilCOORDENAÇÃO DO CURSO ENGENHARIA DE ALIMENTOS/CCSSTCompostos intermetálicos;Propriedades magnéticas;Efeito magnetocalóricoIntermetallic compounds;Magnetic properties;Magnetocaloric effectEstrutura de Líquidos e Sólidos; CristalografiaPROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er).MAGNETIC AND MAGNETHOCALORIC PROPERTIES OF THE RNiGe3 SYSTEM (R = Pr, Nd, I, Dy, Ho and Er).info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFMAinstname:Universidade Federal do Maranhão (UFMA)instacron:UFMAORIGINALRonaldo A. de Araújo.pdfRonaldo A. de Araújo.pdfapplication/pdf6235294http://tedebc.ufma.br:8080/bitstream/tede/2965/2/Ronaldo+A.+de+Ara%C3%BAjo.pdfc28695f18e10477daefcb82d5b93b26eMD52LICENSElicense.txtlicense.txttext/plain; charset=utf-82255http://tedebc.ufma.br:8080/bitstream/tede/2965/1/license.txt97eeade1fce43278e63fe063657f8083MD51tede/29652020-01-08 10:50:49.974oai:tede2: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Biblioteca Digital de Teses e Dissertaçõeshttps://tedebc.ufma.br/jspui/PUBhttp://tedebc.ufma.br:8080/oai/requestrepositorio@ufma.br||repositorio@ufma.bropendoar:21312020-01-08T13:50:49Biblioteca Digital de Teses e Dissertações da UFMA - Universidade Federal do Maranhão (UFMA)false |
dc.title.por.fl_str_mv |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
dc.title.alternative.eng.fl_str_mv |
MAGNETIC AND MAGNETHOCALORIC PROPERTIES OF THE RNiGe3 SYSTEM (R = Pr, Nd, I, Dy, Ho and Er). |
title |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
spellingShingle |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). ARAÚJO, Ronaldo Andrade de Compostos intermetálicos; Propriedades magnéticas; Efeito magnetocalórico Intermetallic compounds; Magnetic properties; Magnetocaloric effect Estrutura de Líquidos e Sólidos; Cristalografia |
title_short |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
title_full |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
title_fullStr |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
title_full_unstemmed |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
title_sort |
PROPRIEDADES MAGNÉTICAS E MAGNETOCALÓRICAS DO SISTEMA RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er). |
author |
ARAÚJO, Ronaldo Andrade de |
author_facet |
ARAÚJO, Ronaldo Andrade de |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
SILVA, Luzeli Moreira da |
dc.contributor.advisor1ID.fl_str_mv |
438.074.022-68 |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/5651616479126344 |
dc.contributor.referee1.fl_str_mv |
SILVA, Luzeli Moreira da |
dc.contributor.referee1ID.fl_str_mv |
438.074.022-68 |
dc.contributor.referee1Lattes.fl_str_mv |
http://lattes.cnpq.br/5651616479126344 |
dc.contributor.referee2.fl_str_mv |
SANTOS, Adenilson Oliveira dos |
dc.contributor.referee2Lattes.fl_str_mv |
http://lattes.cnpq.br/7760219759813661 |
dc.contributor.referee3.fl_str_mv |
SILVA, Leonardo de Sousa |
dc.contributor.authorID.fl_str_mv |
056.750.023-32 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/3515712441056475 |
dc.contributor.author.fl_str_mv |
ARAÚJO, Ronaldo Andrade de |
contributor_str_mv |
SILVA, Luzeli Moreira da SILVA, Luzeli Moreira da SANTOS, Adenilson Oliveira dos SILVA, Leonardo de Sousa |
dc.subject.por.fl_str_mv |
Compostos intermetálicos; Propriedades magnéticas; Efeito magnetocalórico |
topic |
Compostos intermetálicos; Propriedades magnéticas; Efeito magnetocalórico Intermetallic compounds; Magnetic properties; Magnetocaloric effect Estrutura de Líquidos e Sólidos; Cristalografia |
dc.subject.eng.fl_str_mv |
Intermetallic compounds; Magnetic properties; Magnetocaloric effect |
dc.subject.cnpq.fl_str_mv |
Estrutura de Líquidos e Sólidos; Cristalografia |
description |
Structural, magnetic and magnetocaloric properties of the RNiGe3 (R = Pr, Nd, Eu, Dy, Ho and Er) compounds were studied. The samples were synthesized by arc melting technique under argon atmosphere. X-ray diffraction (XRD) measurements and analysis by using the Rietveld method confirm the desired crystallographic phase for all studied samples. Magnetization data shows antiferromagnetic ordering for RNiGe3 compounds, with Néel temperature (TN) around 21 K, 12.5 K, 14 K, 21 K, 9 K and 6 K for R = Pr, Nd, Eu, Dy, Ho and Er, respectively. For T<TN, the compounds NdNiGe3 and EuNiGe3 present an additional transition around 6.1 K and 5 K, respectively, while PrNiGe3 presents two additional transitions around 18.5 and 15.5 K. External magnetic field application induces metamagnetic phase transitions from antiferromagnetic to ferromagnetic state. However, the observed values of the magnetic moments in high magnetic field (H= 60 and 90 kOe) and low temperatures (T = 2 K) are reduced compared to the respective free ions. The metamagnetic critical magnetic field (HC) occurs around 16 kOe, 17.3 kOe, 26.5 kOe, 10.5 kOe and 9.5 kOe, for R = Pr, Nd, Dy, Ho and Er, respectively, and around 20 and 28 kOe for R=Eu. Magnetocaloric effect (MCE) of studies compounds was evaluated by means of the isothermal magnetic entropy change (-ΔSM), in which a broad peak in -ΔSM curve associated with the magnetic transition was observed. In addition, negative MCE was observed for all samples (in ΔH < HC) due to antiferromagnetic ordering. Among the studies compounds, the highest value of -ΔSM was observed for HoNiGe3. The maximum values of -ΔSM (−𝛥𝑆𝑀𝑚𝑎𝑥) and relative cooling power (RCP) observed for RNiGe3 series were respectively, 6.1 J/kg.K and 72.9 J/kg, 4.2 J/kg.K and 68.2 J/kg, 7.5 J/kg.K and 113.6 J/kg, 5.0 J/kg.K and 106 J/kg, 16.7 J/kg.K and 308.5 J/kg, and 11.3 J/kg.K and 214.7 J/kg, for R = Pr, Nd, Eu, Dy, Ho and Er, in ΔH = 50 kOe. These values are comparable to those reported in the literature for other magnetocaloric compounds, in the same temperature range. The obtained results indicate that the RNiGe3 compounds presented interesting magnetocaloric properties for application in magnetic refrigeration at cryogenic temperatures. |
publishDate |
2019 |
dc.date.issued.fl_str_mv |
2019-07-08 |
dc.date.accessioned.fl_str_mv |
2020-01-08T13:50:49Z |
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.citation.fl_str_mv |
ARAÚJO, Ronaldo Andrade de. Propriedades magnéticas e magnetocalóricas do sistema RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er).. 2019. 83 f. Dissertação( Programa de Pós-Graduação em Ciência dos Materiais/CCSST) - Universidade Federal do Maranhão, Imperatriz, 2019. |
dc.identifier.uri.fl_str_mv |
https://tedebc.ufma.br/jspui/handle/tede/tede/2965 |
identifier_str_mv |
ARAÚJO, Ronaldo Andrade de. Propriedades magnéticas e magnetocalóricas do sistema RNiGe3 (R = Pr, Nd, Eu, Dy, Ho e Er).. 2019. 83 f. Dissertação( Programa de Pós-Graduação em Ciência dos Materiais/CCSST) - Universidade Federal do Maranhão, Imperatriz, 2019. |
url |
https://tedebc.ufma.br/jspui/handle/tede/tede/2965 |
dc.language.iso.fl_str_mv |
por |
language |
por |
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.publisher.none.fl_str_mv |
Universidade Federal do Maranhão |
dc.publisher.program.fl_str_mv |
PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIA DOS MATERIAIS/CCSST |
dc.publisher.initials.fl_str_mv |
UFMA |
dc.publisher.country.fl_str_mv |
Brasil |
dc.publisher.department.fl_str_mv |
COORDENAÇÃO DO CURSO ENGENHARIA DE ALIMENTOS/CCSST |
publisher.none.fl_str_mv |
Universidade Federal do Maranhão |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da UFMA instname:Universidade Federal do Maranhão (UFMA) instacron:UFMA |
instname_str |
Universidade Federal do Maranhão (UFMA) |
instacron_str |
UFMA |
institution |
UFMA |
reponame_str |
Biblioteca Digital de Teses e Dissertações da UFMA |
collection |
Biblioteca Digital de Teses e Dissertações da UFMA |
bitstream.url.fl_str_mv |
http://tedebc.ufma.br:8080/bitstream/tede/2965/2/Ronaldo+A.+de+Ara%C3%BAjo.pdf http://tedebc.ufma.br:8080/bitstream/tede/2965/1/license.txt |
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c28695f18e10477daefcb82d5b93b26e 97eeade1fce43278e63fe063657f8083 |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da UFMA - Universidade Federal do Maranhão (UFMA) |
repository.mail.fl_str_mv |
repositorio@ufma.br||repositorio@ufma.br |
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1809926194577014784 |