Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states

CePd2Al2-xGax compounds crystallizing in the tetragonal CaBe2Ge2-type structure (space group P4/nmm) and undergoing a structural phase transition to an orthorhombic structure (Cmme) at low temperatures were studied by means of neutron scattering. The amplitude-modulated magnetic structure of CePd2Al...

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Autores: Klicpera, M., Boehm, M., Dolezal, P., Mutka, Hannu, Koza, M.M., Rols, Stéphane, Adroja, Devashibhai T., Puente-Orench, Inés, Rodríguez-Carvajal, Juan, Javorský, P.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/148752
Acesso em linha:http://hdl.handle.net/10261/148752
Access Level:acceso abierto
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spelling Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" statesKlicpera, M.Boehm, M.Dolezal, P.Mutka, HannuKoza, M.M.Rols, StéphaneAdroja, Devashibhai T.Puente-Orench, InésRodríguez-Carvajal, JuanJavorský, P.CePd2Al2-xGax compounds crystallizing in the tetragonal CaBe2Ge2-type structure (space group P4/nmm) and undergoing a structural phase transition to an orthorhombic structure (Cmme) at low temperatures were studied by means of neutron scattering. The amplitude-modulated magnetic structure of CePd2Al2 is described by an incommensurate propagation vector k - =(δx,12+δy,0) with δx=0.06 and δy=0.04. The magnetic moments order antiferromagnetically within the ab planes stacked along the c axis and are arranged along the direction close to the orthorhombic a axis with a maximum value of 1.5(1) μB/Ce3+. CePd2Ga2 reveals a magnetic structure composed of two components: the first is described by the propagation vector k1 - =(12,12,0), and the second one propagates with k2 - =(0,12,0). The magnetic moments of both components are aligned along the same direction - the orthorhombic [100] direction - and their total amplitude varies depending on the mutual phase of magnetic moment components on each Ce site. The propagation vectors k1 - and k2 - describe also the magnetic structure of substituted CePd2Al2-xGax compounds, except the one with x=0.1.CePd2Al1.9Ga0.1 with magnetic structure described by k - and k1 - stays on the border between pure CePd2Al2 and the rest of the series. Determined magnetic structures are compared with other Ce 112 compounds. Inelastic neutron scattering experiments disclosed three nondispersive magnetic excitations in the paramagnetic state of CePd2Al2, while only two crystal field (CF) excitations are expected from the splitting of ground state J=52 of the Ce3+ ion in a tetragonal/orthorhombic point symmetry. Three magnetic excitations at 1.4, 7.8, and 15.9 meV are observed in the tetragonal phase of CePd2Al2. A structural phase transition to an orthorhombic structure shifts the first excitation up to 3.7 meV, while the other two excitations remain at almost the same energy. The presence of an additional magnetic peak is discussed and described within the Thalmeier-Fulde CF-phonon coupling (i.e., magnetoelastic coupling) model generalized to the tetragonal point symmetry. The second parent compound CePd2Ga2 does not display any sign of additional magnetic excitation. The expected two CF excitations were observed. The development of magnetic excitations in the CePd2Al2-xGax series is discussed and crystal field parameters determined.The work was supported within the program of Large Infrastructures for Research, Experimental Development, and Innovation (Project No. LM2015050) and Research Project No. LG14037 financed by the Ministry of Education, Youth, and Sports, Czech Republic.Peer ReviewedAmerican Physical SocietyMinistry of Education, Youth and Sports (Czech Republic)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]2017201720172017info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionhttp://hdl.handle.net/10261/148752reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1103/PhysRevB.95.085107Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/1487522026-05-22T06:33:51Z
dc.title.none.fl_str_mv Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
title Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
spellingShingle Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
Klicpera, M.
title_short Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
title_full Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
title_fullStr Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
title_full_unstemmed Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
title_sort Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states
dc.creator.none.fl_str_mv Klicpera, M.
Boehm, M.
Dolezal, P.
Mutka, Hannu
Koza, M.M.
Rols, Stéphane
Adroja, Devashibhai T.
Puente-Orench, Inés
Rodríguez-Carvajal, Juan
Javorský, P.
author Klicpera, M.
author_facet Klicpera, M.
Boehm, M.
Dolezal, P.
Mutka, Hannu
Koza, M.M.
Rols, Stéphane
Adroja, Devashibhai T.
Puente-Orench, Inés
Rodríguez-Carvajal, Juan
Javorský, P.
author_role author
author2 Boehm, M.
Dolezal, P.
Mutka, Hannu
Koza, M.M.
Rols, Stéphane
Adroja, Devashibhai T.
Puente-Orench, Inés
Rodríguez-Carvajal, Juan
Javorský, P.
author2_role author
author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Ministry of Education, Youth and Sports (Czech Republic)
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
description CePd2Al2-xGax compounds crystallizing in the tetragonal CaBe2Ge2-type structure (space group P4/nmm) and undergoing a structural phase transition to an orthorhombic structure (Cmme) at low temperatures were studied by means of neutron scattering. The amplitude-modulated magnetic structure of CePd2Al2 is described by an incommensurate propagation vector k - =(δx,12+δy,0) with δx=0.06 and δy=0.04. The magnetic moments order antiferromagnetically within the ab planes stacked along the c axis and are arranged along the direction close to the orthorhombic a axis with a maximum value of 1.5(1) μB/Ce3+. CePd2Ga2 reveals a magnetic structure composed of two components: the first is described by the propagation vector k1 - =(12,12,0), and the second one propagates with k2 - =(0,12,0). The magnetic moments of both components are aligned along the same direction - the orthorhombic [100] direction - and their total amplitude varies depending on the mutual phase of magnetic moment components on each Ce site. The propagation vectors k1 - and k2 - describe also the magnetic structure of substituted CePd2Al2-xGax compounds, except the one with x=0.1.CePd2Al1.9Ga0.1 with magnetic structure described by k - and k1 - stays on the border between pure CePd2Al2 and the rest of the series. Determined magnetic structures are compared with other Ce 112 compounds. Inelastic neutron scattering experiments disclosed three nondispersive magnetic excitations in the paramagnetic state of CePd2Al2, while only two crystal field (CF) excitations are expected from the splitting of ground state J=52 of the Ce3+ ion in a tetragonal/orthorhombic point symmetry. Three magnetic excitations at 1.4, 7.8, and 15.9 meV are observed in the tetragonal phase of CePd2Al2. A structural phase transition to an orthorhombic structure shifts the first excitation up to 3.7 meV, while the other two excitations remain at almost the same energy. The presence of an additional magnetic peak is discussed and described within the Thalmeier-Fulde CF-phonon coupling (i.e., magnetoelastic coupling) model generalized to the tetragonal point symmetry. The second parent compound CePd2Ga2 does not display any sign of additional magnetic excitation. The expected two CF excitations were observed. The development of magnetic excitations in the CePd2Al2-xGax series is discussed and crystal field parameters determined.
publishDate 2017
dc.date.none.fl_str_mv 2017
2017
2017
2017
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Publisher's version
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/148752
url http://hdl.handle.net/10261/148752
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1103/PhysRevB.95.085107
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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 reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15.811543

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