On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study

Autores
Makinistian, Leonardo; Faiz, Muhammad M.; Panguluri, Raghava P.; Balke, B.; Wurmehl, S.; Felser, C.; Albanesi, Eduardo Aldo; Petukhov, A. G.; Nadgorny, B.
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Co2FeSi, a Heusler alloy with the highest magnetic moment per unit cell and the highest Curie temperature, has largely been described theoretically as a half-metal. This conclusion, however, disagrees with point contact Andreev reflection (PCAR) spectroscopy measurements, which give much lower values of spin polarization, P. Here, we present the spin polarization measurements of Co2FeSi by the PCAR technique, along with a thorough computational exploration, within the DFT and a GGA+U approach, of the Coulomb exchange U parameters for Co and Fe atoms, taking into account spin-orbit coupling. We find that the orbital contribution (mo) to the total magnetic moment (mT) is significant, since it is at least 3 times greater than the experimental uncertainty of mT. The account of mo radically affects the acceptable values of U. Specifically, we find no values of U that would simultaneously satisfy the experimental values of the magnetic moment and result in the half-metallicity of Co2FeSi. On the other hand, the ranges of U that we report as acceptable are compatible with spin polarization measurements (ours and the ones found in the literature), which all are within approximately the 40–60 % range. Thus, based on reconciling experimental and computational results, we conclude that (a) spin-orbit coupling cannot be neglected in calculating Co2FeSi magnetic properties, and (b) Co2FeSi Heusler alloy is not half-metallic. We believe that our approach can be applied to other Heusler alloys such as Co2FeAl.
Fil: Makinistian, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; Argentina
Fil: Faiz, Muhammad M.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
Fil: Panguluri, Raghava P.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
Fil: Balke, B.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Wurmehl, S.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Felser, C.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Albanesi, Eduardo Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; Argentina
Fil: Petukhov, A. G.. South Dakota School of Mines. Department of Physics; Estados Unidos
Fil: Nadgorny, B.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
Materia
Half-Metallicity
Heusler-Alloy
Co2fesi
Point-Contact Andreev Reflection
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/6539
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/6539
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio studyMakinistian, LeonardoFaiz, Muhammad M.Panguluri, Raghava P.Balke, B.Wurmehl, S.Felser, C.Albanesi, Eduardo AldoPetukhov, A. G.Nadgorny, B.Half-MetallicityHeusler-AlloyCo2fesiPoint-Contact Andreev Reflectionhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Co2FeSi, a Heusler alloy with the highest magnetic moment per unit cell and the highest Curie temperature, has largely been described theoretically as a half-metal. This conclusion, however, disagrees with point contact Andreev reflection (PCAR) spectroscopy measurements, which give much lower values of spin polarization, P. Here, we present the spin polarization measurements of Co2FeSi by the PCAR technique, along with a thorough computational exploration, within the DFT and a GGA+U approach, of the Coulomb exchange U parameters for Co and Fe atoms, taking into account spin-orbit coupling. We find that the orbital contribution (mo) to the total magnetic moment (mT) is significant, since it is at least 3 times greater than the experimental uncertainty of mT. The account of mo radically affects the acceptable values of U. Specifically, we find no values of U that would simultaneously satisfy the experimental values of the magnetic moment and result in the half-metallicity of Co2FeSi. On the other hand, the ranges of U that we report as acceptable are compatible with spin polarization measurements (ours and the ones found in the literature), which all are within approximately the 40–60 % range. Thus, based on reconciling experimental and computational results, we conclude that (a) spin-orbit coupling cannot be neglected in calculating Co2FeSi magnetic properties, and (b) Co2FeSi Heusler alloy is not half-metallic. We believe that our approach can be applied to other Heusler alloys such as Co2FeAl.Fil: Makinistian, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; ArgentinaFil: Faiz, Muhammad M.. Wayne State University. Department of Physics and Astronomy; Estados UnidosFil: Panguluri, Raghava P.. Wayne State University. Department of Physics and Astronomy; Estados UnidosFil: Balke, B.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; AlemaniaFil: Wurmehl, S.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; AlemaniaFil: Felser, C.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; AlemaniaFil: Albanesi, Eduardo Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; ArgentinaFil: Petukhov, A. G.. South Dakota School of Mines. Department of Physics; Estados UnidosFil: Nadgorny, B.. Wayne State University. Department of Physics and Astronomy; Estados UnidosAmerican Physical Society2013-06info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/6539Makinistian, Leonardo; Faiz, Muhammad M.; Panguluri, Raghava P.; Balke, B.; Wurmehl, S.; et al.; On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study; American Physical Society; Physical Review B; 87; 22; 6-2013; 220402-2204051098-0121enginfo:eu-repo/semantics/altIdentifier/url/http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.220402info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.87.220402info:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/altIdentifier/arxiv/1212.0168v1info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1212.0168v1info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:13:24Zoai:ri.conicet.gov.ar:11336/6539instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 15:13:24.583CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
title On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
spellingShingle On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
Makinistian, Leonardo
Half-Metallicity
Heusler-Alloy
Co2fesi
Point-Contact Andreev Reflection
title_short On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
title_full On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
title_fullStr On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
title_full_unstemmed On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
title_sort On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study
dc.creator.none.fl_str_mv Makinistian, Leonardo
Faiz, Muhammad M.
Panguluri, Raghava P.
Balke, B.
Wurmehl, S.
Felser, C.
Albanesi, Eduardo Aldo
Petukhov, A. G.
Nadgorny, B.
author Makinistian, Leonardo
author_facet Makinistian, Leonardo
Faiz, Muhammad M.
Panguluri, Raghava P.
Balke, B.
Wurmehl, S.
Felser, C.
Albanesi, Eduardo Aldo
Petukhov, A. G.
Nadgorny, B.
author_role author
author2 Faiz, Muhammad M.
Panguluri, Raghava P.
Balke, B.
Wurmehl, S.
Felser, C.
Albanesi, Eduardo Aldo
Petukhov, A. G.
Nadgorny, B.
author2_role author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Half-Metallicity
Heusler-Alloy
Co2fesi
Point-Contact Andreev Reflection
topic Half-Metallicity
Heusler-Alloy
Co2fesi
Point-Contact Andreev Reflection
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Co2FeSi, a Heusler alloy with the highest magnetic moment per unit cell and the highest Curie temperature, has largely been described theoretically as a half-metal. This conclusion, however, disagrees with point contact Andreev reflection (PCAR) spectroscopy measurements, which give much lower values of spin polarization, P. Here, we present the spin polarization measurements of Co2FeSi by the PCAR technique, along with a thorough computational exploration, within the DFT and a GGA+U approach, of the Coulomb exchange U parameters for Co and Fe atoms, taking into account spin-orbit coupling. We find that the orbital contribution (mo) to the total magnetic moment (mT) is significant, since it is at least 3 times greater than the experimental uncertainty of mT. The account of mo radically affects the acceptable values of U. Specifically, we find no values of U that would simultaneously satisfy the experimental values of the magnetic moment and result in the half-metallicity of Co2FeSi. On the other hand, the ranges of U that we report as acceptable are compatible with spin polarization measurements (ours and the ones found in the literature), which all are within approximately the 40–60 % range. Thus, based on reconciling experimental and computational results, we conclude that (a) spin-orbit coupling cannot be neglected in calculating Co2FeSi magnetic properties, and (b) Co2FeSi Heusler alloy is not half-metallic. We believe that our approach can be applied to other Heusler alloys such as Co2FeAl.
Fil: Makinistian, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; Argentina
Fil: Faiz, Muhammad M.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
Fil: Panguluri, Raghava P.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
Fil: Balke, B.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Wurmehl, S.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Felser, C.. Johannes Gutenberg-Universität. Institut fur Anorganische Chemie und Analytische Chemie; Alemania
Fil: Albanesi, Eduardo Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentina. Universidad Nacional de Entre Rios; Argentina
Fil: Petukhov, A. G.. South Dakota School of Mines. Department of Physics; Estados Unidos
Fil: Nadgorny, B.. Wayne State University. Department of Physics and Astronomy; Estados Unidos
description Co2FeSi, a Heusler alloy with the highest magnetic moment per unit cell and the highest Curie temperature, has largely been described theoretically as a half-metal. This conclusion, however, disagrees with point contact Andreev reflection (PCAR) spectroscopy measurements, which give much lower values of spin polarization, P. Here, we present the spin polarization measurements of Co2FeSi by the PCAR technique, along with a thorough computational exploration, within the DFT and a GGA+U approach, of the Coulomb exchange U parameters for Co and Fe atoms, taking into account spin-orbit coupling. We find that the orbital contribution (mo) to the total magnetic moment (mT) is significant, since it is at least 3 times greater than the experimental uncertainty of mT. The account of mo radically affects the acceptable values of U. Specifically, we find no values of U that would simultaneously satisfy the experimental values of the magnetic moment and result in the half-metallicity of Co2FeSi. On the other hand, the ranges of U that we report as acceptable are compatible with spin polarization measurements (ours and the ones found in the literature), which all are within approximately the 40–60 % range. Thus, based on reconciling experimental and computational results, we conclude that (a) spin-orbit coupling cannot be neglected in calculating Co2FeSi magnetic properties, and (b) Co2FeSi Heusler alloy is not half-metallic. We believe that our approach can be applied to other Heusler alloys such as Co2FeAl.
publishDate 2013
dc.date.none.fl_str_mv 2013-06
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/6539
Makinistian, Leonardo; Faiz, Muhammad M.; Panguluri, Raghava P.; Balke, B.; Wurmehl, S.; et al.; On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study; American Physical Society; Physical Review B; 87; 22; 6-2013; 220402-220405
1098-0121
url http://hdl.handle.net/11336/6539
identifier_str_mv Makinistian, Leonardo; Faiz, Muhammad M.; Panguluri, Raghava P.; Balke, B.; Wurmehl, S.; et al.; On the half-metallicity of Co2FeSi Heusler alloy: Point-contact Andreev reflection spectroscopy and ab initio study; American Physical Society; Physical Review B; 87; 22; 6-2013; 220402-220405
1098-0121
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.220402
info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.87.220402
info:eu-repo/semantics/altIdentifier/doi/
info:eu-repo/semantics/altIdentifier/arxiv/1212.0168v1
info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1212.0168v1
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.22299

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