Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations

Perturbed angular correlation (PAC) spectroscopy has been used to investigate the electric field gradient (EFG) at the probe nucleus ^(111)In/^(111)Cd in the paramagnetic phase of the rare earth (R)-aluminium compounds RAl₂ for all R elements and Y and in RAl₃ for R=Gd,Tm,Yb,Lu. The nuclear electric...

ver descrição completa

Detalhes bibliográficos
Autores: Forker, F., Presa Muñoz De Toro, Patricia Marcela De La
Tipo de documento: artigo
Data de publicação:2007
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositório:Docta Complutense
Idioma:inglês
OAI Identifier:oai:docta.ucm.es:20.500.14352/52150
Acesso em linha:https://hdl.handle.net/20.500.14352/52150
Access Level:Acceso aberto
Palavra-chave:538.9
Temperature-dependence
Crystal-field
Hyperfine interactions
Intermediate-valence
Metals
YbAl₃
Relaxation
Impurities
Diffusion
Pressure
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
id ES_745a6993e0f084e8906d4e42f47d031c
oai_identifier_str oai:docta.ucm.es:20.500.14352/52150
network_acronym_str ES
network_name_str España
repository_id_str
spelling Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlationsForker, F.Presa Muñoz De Toro, Patricia Marcela De La538.9Temperature-dependenceCrystal-fieldHyperfine interactionsIntermediate-valenceMetalsYbAl₃RelaxationImpuritiesDiffusionPressureFísica de materialesFísica del estado sólido2211 Física del Estado SólidoPerturbed angular correlation (PAC) spectroscopy has been used to investigate the electric field gradient (EFG) at the probe nucleus ^(111)In/^(111)Cd in the paramagnetic phase of the rare earth (R)-aluminium compounds RAl₂ for all R elements and Y and in RAl₃ for R=Gd,Tm,Yb,Lu. The nuclear electric quadrupole interaction (QI) between the EFG and the ^(111)Cd quadrupole moment was measured as a function of temperature in the range T_c < T ≤ 1200 K. In the second half of the RAl₂ series and in the RAl₃ compounds, except for YbAl₃, the quadrupole frequency v_q shows the monotonous decrease with increasing temperature normally observed with closed-shell probe nuclei in metallic systems. In the early members of the RAl₂ series, however, v_q (T) passes through a maximum at T similar to 300 K. It is proposed that this unusual behavior reflects a contribution of the 4f shell of the R constituents to the EFG at the Al site which is quenched at higher temperatures by thermal averaging of the 4f quadrupole moment. In the intermediate-valence compound YbAl₃ the temperature dependence of the QI exhibits a shallow maximum which can be related to the temperature variation of the 4f hole occupation. Furthermore the PAC spectra provide information on the site preference of the ^111In solutes in RAl₂ for different R constituents and temperatures. In two-phase samples containing RAl₂ and RAl₃ with AuCu₃ structure, at T < 900 K the solutes show a very pronounced preference for the Al site of RAl₃, but at higher temperatures they migrate to the Al site of RAl₂. Jumps of the ^(111)In/ ^(111)Cd probes on the Al sublattice of RAl₃ compounds with AuCu₃ structure (R=Tm,Yb,Lu) lead to nuclear spin relaxation of ^(111)Cd. The temperature dependence of the relaxation rates shows an Arrhenius behavior with jump activation enthalpies E_(A)=1.6(1) eV for R=Tm, Lu and E_(A)=1.2(1) eV for R=Yb.American Physical SocietyUniversidad Complutense de Madrid20072007-09-0120072007-09-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/52150reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/521502026-06-02T12:44:21Z
dc.title.none.fl_str_mv Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
title Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
spellingShingle Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
Forker, F.
538.9
Temperature-dependence
Crystal-field
Hyperfine interactions
Intermediate-valence
Metals
YbAl₃
Relaxation
Impurities
Diffusion
Pressure
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
title_short Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
title_full Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
title_fullStr Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
title_full_unstemmed Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
title_sort Electric field gradients in the rare earth–aluminium compounds RAl₂ and RAl₃ studied by ^(111)Cd perturbed angular correlations
dc.creator.none.fl_str_mv Forker, F.
Presa Muñoz De Toro, Patricia Marcela De La
author Forker, F.
author_facet Forker, F.
Presa Muñoz De Toro, Patricia Marcela De La
author_role author
author2 Presa Muñoz De Toro, Patricia Marcela De La
author2_role author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 538.9
Temperature-dependence
Crystal-field
Hyperfine interactions
Intermediate-valence
Metals
YbAl₃
Relaxation
Impurities
Diffusion
Pressure
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
topic 538.9
Temperature-dependence
Crystal-field
Hyperfine interactions
Intermediate-valence
Metals
YbAl₃
Relaxation
Impurities
Diffusion
Pressure
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
description Perturbed angular correlation (PAC) spectroscopy has been used to investigate the electric field gradient (EFG) at the probe nucleus ^(111)In/^(111)Cd in the paramagnetic phase of the rare earth (R)-aluminium compounds RAl₂ for all R elements and Y and in RAl₃ for R=Gd,Tm,Yb,Lu. The nuclear electric quadrupole interaction (QI) between the EFG and the ^(111)Cd quadrupole moment was measured as a function of temperature in the range T_c < T ≤ 1200 K. In the second half of the RAl₂ series and in the RAl₃ compounds, except for YbAl₃, the quadrupole frequency v_q shows the monotonous decrease with increasing temperature normally observed with closed-shell probe nuclei in metallic systems. In the early members of the RAl₂ series, however, v_q (T) passes through a maximum at T similar to 300 K. It is proposed that this unusual behavior reflects a contribution of the 4f shell of the R constituents to the EFG at the Al site which is quenched at higher temperatures by thermal averaging of the 4f quadrupole moment. In the intermediate-valence compound YbAl₃ the temperature dependence of the QI exhibits a shallow maximum which can be related to the temperature variation of the 4f hole occupation. Furthermore the PAC spectra provide information on the site preference of the ^111In solutes in RAl₂ for different R constituents and temperatures. In two-phase samples containing RAl₂ and RAl₃ with AuCu₃ structure, at T < 900 K the solutes show a very pronounced preference for the Al site of RAl₃, but at higher temperatures they migrate to the Al site of RAl₂. Jumps of the ^(111)In/ ^(111)Cd probes on the Al sublattice of RAl₃ compounds with AuCu₃ structure (R=Tm,Yb,Lu) lead to nuclear spin relaxation of ^(111)Cd. The temperature dependence of the relaxation rates shows an Arrhenius behavior with jump activation enthalpies E_(A)=1.6(1) eV for R=Tm, Lu and E_(A)=1.2(1) eV for R=Yb.
publishDate 2007
dc.date.none.fl_str_mv 2007
2007-09-01
2007
2007-09-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/52150
url https://hdl.handle.net/20.500.14352/52150
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.format.none.fl_str_mv 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:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869410889207119872
score 15,300724

Registros relacionados