Reduction of the Yb valence in YbAl3 nanoparticles

Measurements of specific heat, dc magnetic susceptibility, and Yb LII and LIII x-ray absorption near-edge structure XANES and extended x-ray absorption fine structure EXAFS on YbAl3 milled alloys are reported. X-ray diffraction patterns are consistent with a reduction in particle size down to 10 nm...

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Autores: Rojas Pupo, Daniel|||0000-0002-5620-8586, Fernández Barquín, Luis|||0000-0003-4722-3722, Espeso Martínez, José Ignacio|||0000-0002-4018-7186, Rodríguez Fernández, Jesús|||0000-0002-4046-2969, Chaboy, J.
Tipo de recurso: artículo
Fecha de publicación:2008
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/520
Acceso en línea:http://hdl.handle.net/10902/520
Access Level:acceso abierto
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spelling Reduction of the Yb valence in YbAl3 nanoparticlesRojas Pupo, Daniel|||0000-0002-5620-8586Fernández Barquín, Luis|||0000-0003-4722-3722Espeso Martínez, José Ignacio|||0000-0002-4018-7186Rodríguez Fernández, Jesús|||0000-0002-4046-2969Chaboy, J.Measurements of specific heat, dc magnetic susceptibility, and Yb LII and LIII x-ray absorption near-edge structure XANES and extended x-ray absorption fine structure EXAFS on YbAl3 milled alloys are reported. X-ray diffraction patterns are consistent with a reduction in particle size down to 10 nm and an increase in the lattice strain up to 0.4% for 120 h of milling time. A decrease in the mean valence from 2.86 for the unmilled alloy to 2.70 for 120 h milled YbAl3 is obtained from the analysis of XANES spectra. From the analysis of spectra in the EXAFS region, an increase in the mean-square disorder of neighbor distance with milling time is detected in good agreement with the results of x-ray diffraction. Size effects strongly influence the magnetic and thermal properties. The value for the maximum of the magnetic susceptibility decreases around 30% for 120 h milled alloy and an excess specific heat, with a peak around 40 K in the milled samples, is derived. These changes in the physical properties along the milled YbAl3 alloys are associated with the reduction in particle size. Such a reduction leads to the existence of a large number of Yb2+ atoms at the surface with respect to the bulk affecting the overall electronic state.American Physical SocietyUniversidad de Cantabria20082008-09-16journal articlehttp://purl.org/coar/resource_type/c_6501NAhttp://purl.org/coar/version/c_be7fb7dd8ff6fe43info:eu-repo/semantics/articlehttp://hdl.handle.net/10902/520Physical Review. B, Condensed matter and materials physics, vol.78, 2008, article number 094412.reponame:UCrea Repositorio Abierto de la Universidad de Cantabriainstname:Universidad de Cantabria (UC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:repositorio.unican.es:10902/5202026-06-02T12:39:31Z
dc.title.none.fl_str_mv Reduction of the Yb valence in YbAl3 nanoparticles
title Reduction of the Yb valence in YbAl3 nanoparticles
spellingShingle Reduction of the Yb valence in YbAl3 nanoparticles
Rojas Pupo, Daniel|||0000-0002-5620-8586
title_short Reduction of the Yb valence in YbAl3 nanoparticles
title_full Reduction of the Yb valence in YbAl3 nanoparticles
title_fullStr Reduction of the Yb valence in YbAl3 nanoparticles
title_full_unstemmed Reduction of the Yb valence in YbAl3 nanoparticles
title_sort Reduction of the Yb valence in YbAl3 nanoparticles
dc.creator.none.fl_str_mv Rojas Pupo, Daniel|||0000-0002-5620-8586
Fernández Barquín, Luis|||0000-0003-4722-3722
Espeso Martínez, José Ignacio|||0000-0002-4018-7186
Rodríguez Fernández, Jesús|||0000-0002-4046-2969
Chaboy, J.
author Rojas Pupo, Daniel|||0000-0002-5620-8586
author_facet Rojas Pupo, Daniel|||0000-0002-5620-8586
Fernández Barquín, Luis|||0000-0003-4722-3722
Espeso Martínez, José Ignacio|||0000-0002-4018-7186
Rodríguez Fernández, Jesús|||0000-0002-4046-2969
Chaboy, J.
author_role author
author2 Fernández Barquín, Luis|||0000-0003-4722-3722
Espeso Martínez, José Ignacio|||0000-0002-4018-7186
Rodríguez Fernández, Jesús|||0000-0002-4046-2969
Chaboy, J.
author2_role author
author
author
author
dc.contributor.none.fl_str_mv Universidad de Cantabria
description Measurements of specific heat, dc magnetic susceptibility, and Yb LII and LIII x-ray absorption near-edge structure XANES and extended x-ray absorption fine structure EXAFS on YbAl3 milled alloys are reported. X-ray diffraction patterns are consistent with a reduction in particle size down to 10 nm and an increase in the lattice strain up to 0.4% for 120 h of milling time. A decrease in the mean valence from 2.86 for the unmilled alloy to 2.70 for 120 h milled YbAl3 is obtained from the analysis of XANES spectra. From the analysis of spectra in the EXAFS region, an increase in the mean-square disorder of neighbor distance with milling time is detected in good agreement with the results of x-ray diffraction. Size effects strongly influence the magnetic and thermal properties. The value for the maximum of the magnetic susceptibility decreases around 30% for 120 h milled alloy and an excess specific heat, with a peak around 40 K in the milled samples, is derived. These changes in the physical properties along the milled YbAl3 alloys are associated with the reduction in particle size. Such a reduction leads to the existence of a large number of Yb2+ atoms at the surface with respect to the bulk affecting the overall electronic state.
publishDate 2008
dc.date.none.fl_str_mv 2008
2008-09-16
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
NA
http://purl.org/coar/version/c_be7fb7dd8ff6fe43
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10902/520
url http://hdl.handle.net/10902/520
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv Physical Review. B, Condensed matter and materials physics, vol.78, 2008, article number 094412.
reponame:UCrea Repositorio Abierto de la Universidad de Cantabria
instname:Universidad de Cantabria (UC)
instname_str Universidad de Cantabria (UC)
reponame_str UCrea Repositorio Abierto de la Universidad de Cantabria
collection UCrea Repositorio Abierto de la Universidad de Cantabria
repository.name.fl_str_mv
repository.mail.fl_str_mv
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