Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1103/PhysRevB.102.024436 http://hdl.handle.net/11449/221533 |
Resumo: | The delicate balance between spin-orbit coupling, Coulomb repulsion, and crystalline electric field interactions observed in Ir-based oxides is usually manifested as exotic magnetic behavior. Here we investigate the evolution of the exchange coupling between Co and Ir for partial La substitution by Ca in La2CoIrO6. A great advantage of the use of Ca2+ as a replacement for La3+ is the similarity of their ionic radii. Thus, the observed magnetic changes can more easily be associated with electronic variations. A thorough investigation of the structural, electronic, and magnetic properties of the La2-xCaxCoIrO6 system was carried out by means of synchrotron x-ray powder diffraction, muon spin rotation and relaxation (μSR), AC and DC magnetization, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism, Raman spectroscopy, electrical resistivity, and dielectric permittivity. Our XAS results show that up to 25% Ca substitution at the La site results in the emergence of Co3+, possibly in a high-spin state, while the introduction of a larger amount of Ca leads to an increase in the Ir valence. The competing magnetic interactions resulting from the mixed valences lead to the coexistence of a magnetically ordered and an emerging spin-glass (SG) state for the doped samples. Our μSR results indicate that for La2CoIrO6 a nearly constant fraction of a paramagnetic (PM) phase persists down to low temperatures, possibly related to the presence of a small amount of Ir3+ and to the antisite disorder at Co/Ir sites. For doped compounds the PM phase freezes below 30 K, but there is still some dynamics associated with the SG. The dielectric data obtained for the parent compound and the one with 25% Ca doping indicate a possible magnetodielectric effect, which is discussed in terms of the electron hopping between the transition-metal ions, the antisite disorder at Co/Ir sites, and the distorted crystalline structure. |
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Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6The delicate balance between spin-orbit coupling, Coulomb repulsion, and crystalline electric field interactions observed in Ir-based oxides is usually manifested as exotic magnetic behavior. Here we investigate the evolution of the exchange coupling between Co and Ir for partial La substitution by Ca in La2CoIrO6. A great advantage of the use of Ca2+ as a replacement for La3+ is the similarity of their ionic radii. Thus, the observed magnetic changes can more easily be associated with electronic variations. A thorough investigation of the structural, electronic, and magnetic properties of the La2-xCaxCoIrO6 system was carried out by means of synchrotron x-ray powder diffraction, muon spin rotation and relaxation (μSR), AC and DC magnetization, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism, Raman spectroscopy, electrical resistivity, and dielectric permittivity. Our XAS results show that up to 25% Ca substitution at the La site results in the emergence of Co3+, possibly in a high-spin state, while the introduction of a larger amount of Ca leads to an increase in the Ir valence. The competing magnetic interactions resulting from the mixed valences lead to the coexistence of a magnetically ordered and an emerging spin-glass (SG) state for the doped samples. Our μSR results indicate that for La2CoIrO6 a nearly constant fraction of a paramagnetic (PM) phase persists down to low temperatures, possibly related to the presence of a small amount of Ir3+ and to the antisite disorder at Co/Ir sites. For doped compounds the PM phase freezes below 30 K, but there is still some dynamics associated with the SG. The dielectric data obtained for the parent compound and the one with 25% Ca doping indicate a possible magnetodielectric effect, which is discussed in terms of the electron hopping between the transition-metal ions, the antisite disorder at Co/Ir sites, and the distorted crystalline structure.Instituto de Física Universidade Federal de GoiásInstitut für Physik der Kondensierten Materie Technische Universität BraunschweigInstitut für Festkörper- und Materialphysik Technische Universität DresdenCentro Brasileiro de Pesquisas FísicasInstituto de Física Gleb Wataghin UNICAMPLaboratório Nacional de Luz Síncrotron Centro Nacional de Pesquisa em Energia e MateriaisDepartment of Physics and Chemistry São Paulo State UniversityDepartment of Physics and Chemistry São Paulo State UniversityUniversidade Federal de Goiás (UFG)Technische Universität BraunschweigTechnische Universität DresdenCentro Brasileiro de Pesquisas FísicasUniversidade Estadual de Campinas (UNICAMP)Centro Nacional de Pesquisa em Energia e MateriaisUniversidade Estadual Paulista (UNESP)Bufaiçal, L.Sadrollahi, E.Litterst, F. J.Rigitano, D.Granado, E.Coutrim, L. T.Araújo, E. B. [UNESP]Fontes, M. B.Baggio-Saitovitch, E.Bittar, E. M.2022-04-28T19:29:15Z2022-04-28T19:29:15Z2020-07-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1103/PhysRevB.102.024436Physical Review B, v. 102, n. 2, 2020.2469-99692469-9950http://hdl.handle.net/11449/22153310.1103/PhysRevB.102.0244362-s2.0-85089597438Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengPhysical Review Binfo:eu-repo/semantics/openAccess2022-04-28T19:29:15Zoai:repositorio.unesp.br:11449/221533Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462022-04-28T19:29:15Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
title |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
spellingShingle |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 Bufaiçal, L. |
title_short |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
title_full |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
title_fullStr |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
title_full_unstemmed |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
title_sort |
Effect of structural and magnetic disorder on the 3d-5d exchange interactions in La2-xCaxCoIrO6 |
author |
Bufaiçal, L. |
author_facet |
Bufaiçal, L. Sadrollahi, E. Litterst, F. J. Rigitano, D. Granado, E. Coutrim, L. T. Araújo, E. B. [UNESP] Fontes, M. B. Baggio-Saitovitch, E. Bittar, E. M. |
author_role |
author |
author2 |
Sadrollahi, E. Litterst, F. J. Rigitano, D. Granado, E. Coutrim, L. T. Araújo, E. B. [UNESP] Fontes, M. B. Baggio-Saitovitch, E. Bittar, E. M. |
author2_role |
author author author author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal de Goiás (UFG) Technische Universität Braunschweig Technische Universität Dresden Centro Brasileiro de Pesquisas Físicas Universidade Estadual de Campinas (UNICAMP) Centro Nacional de Pesquisa em Energia e Materiais Universidade Estadual Paulista (UNESP) |
dc.contributor.author.fl_str_mv |
Bufaiçal, L. Sadrollahi, E. Litterst, F. J. Rigitano, D. Granado, E. Coutrim, L. T. Araújo, E. B. [UNESP] Fontes, M. B. Baggio-Saitovitch, E. Bittar, E. M. |
description |
The delicate balance between spin-orbit coupling, Coulomb repulsion, and crystalline electric field interactions observed in Ir-based oxides is usually manifested as exotic magnetic behavior. Here we investigate the evolution of the exchange coupling between Co and Ir for partial La substitution by Ca in La2CoIrO6. A great advantage of the use of Ca2+ as a replacement for La3+ is the similarity of their ionic radii. Thus, the observed magnetic changes can more easily be associated with electronic variations. A thorough investigation of the structural, electronic, and magnetic properties of the La2-xCaxCoIrO6 system was carried out by means of synchrotron x-ray powder diffraction, muon spin rotation and relaxation (μSR), AC and DC magnetization, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism, Raman spectroscopy, electrical resistivity, and dielectric permittivity. Our XAS results show that up to 25% Ca substitution at the La site results in the emergence of Co3+, possibly in a high-spin state, while the introduction of a larger amount of Ca leads to an increase in the Ir valence. The competing magnetic interactions resulting from the mixed valences lead to the coexistence of a magnetically ordered and an emerging spin-glass (SG) state for the doped samples. Our μSR results indicate that for La2CoIrO6 a nearly constant fraction of a paramagnetic (PM) phase persists down to low temperatures, possibly related to the presence of a small amount of Ir3+ and to the antisite disorder at Co/Ir sites. For doped compounds the PM phase freezes below 30 K, but there is still some dynamics associated with the SG. The dielectric data obtained for the parent compound and the one with 25% Ca doping indicate a possible magnetodielectric effect, which is discussed in terms of the electron hopping between the transition-metal ions, the antisite disorder at Co/Ir sites, and the distorted crystalline structure. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-07-01 2022-04-28T19:29:15Z 2022-04-28T19:29:15Z |
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.uri.fl_str_mv |
http://dx.doi.org/10.1103/PhysRevB.102.024436 Physical Review B, v. 102, n. 2, 2020. 2469-9969 2469-9950 http://hdl.handle.net/11449/221533 10.1103/PhysRevB.102.024436 2-s2.0-85089597438 |
url |
http://dx.doi.org/10.1103/PhysRevB.102.024436 http://hdl.handle.net/11449/221533 |
identifier_str_mv |
Physical Review B, v. 102, n. 2, 2020. 2469-9969 2469-9950 10.1103/PhysRevB.102.024436 2-s2.0-85089597438 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Physical Review B |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
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1803649265312989184 |