The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data

Autores
Mayer, Sergio Federico; Falcon, Horacio; Fernández Díaz, María Teresa; Alonso, José Antonio
Año de publicación
2018
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Three defect pyrochlores KNbWO6·xH2O, KNbTeO6 and KSbWO6 were synthesized by solid state reaction at 750 °C, from stoichiometric mixtures of K2C2O4, Sb2O3, Nb2O5, WO3 and 20% excess TeO2. A neutron powder diffraction (NPD) data analysis allowed unveiling some structural features. They are all defined in the cubic (Formula Presented) space group symmetry, with α = 10.5068(1) Å, 10.2466(1) Å and 10.2377(1) Å, respectively. Difference Fourier synthesis for KNbWO6·xH2O clearly showed the presence of crystallization water, with extra O’ oxygen and H+ atoms that were located from NPD data. These O’ oxygen atoms are placed at 32e Wyckoff sites, conforming a K2O’ sublattice interpenetrated with the covalent framework constituted by (Nb,W)O6 octahedra. The H+ ions coordinate the O’ atoms at partially occupied 96g Wyckoff sites while K+ ions shift also along 32e sites, but closer to the 16c special site (0,0,0). By contrast, extra H2O molecules are absent in the other two pyrochlores: in KNbTeO6 and KSbWO6 K+ ions are shifted along 32e (x,x,x) sites further away from the origin than for the previous material, and the higher covalency of the octahedral network determines more compact structures, with shorter B-O distances and narrower B-O-B angles in the proposed AB2O6 defect pyrochlore structure.
Fil: Mayer, Sergio Federico. Instituto de Ciencia de Materiales de Madrid; España. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina
Fil: Falcon, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentina
Fil: Fernández Díaz, María Teresa. Institut Laue Langevin; Francia
Fil: Alonso, José Antonio. Instituto de Ciencia de Materiales de Madrid; España
Materia
AB2O6
KNBTEO6
KNBWO6
KSBWO6
NEUTRON POWDER DIFFRACTION
PYROCHLORES
RIETVELD
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/93570
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/93570
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction dataMayer, Sergio FedericoFalcon, HoracioFernández Díaz, María TeresaAlonso, José AntonioAB2O6KNBTEO6KNBWO6KSBWO6NEUTRON POWDER DIFFRACTIONPYROCHLORESRIETVELDhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Three defect pyrochlores KNbWO6·xH2O, KNbTeO6 and KSbWO6 were synthesized by solid state reaction at 750 °C, from stoichiometric mixtures of K2C2O4, Sb2O3, Nb2O5, WO3 and 20% excess TeO2. A neutron powder diffraction (NPD) data analysis allowed unveiling some structural features. They are all defined in the cubic (Formula Presented) space group symmetry, with α = 10.5068(1) Å, 10.2466(1) Å and 10.2377(1) Å, respectively. Difference Fourier synthesis for KNbWO6·xH2O clearly showed the presence of crystallization water, with extra O’ oxygen and H+ atoms that were located from NPD data. These O’ oxygen atoms are placed at 32e Wyckoff sites, conforming a K2O’ sublattice interpenetrated with the covalent framework constituted by (Nb,W)O6 octahedra. The H+ ions coordinate the O’ atoms at partially occupied 96g Wyckoff sites while K+ ions shift also along 32e sites, but closer to the 16c special site (0,0,0). By contrast, extra H2O molecules are absent in the other two pyrochlores: in KNbTeO6 and KSbWO6 K+ ions are shifted along 32e (x,x,x) sites further away from the origin than for the previous material, and the higher covalency of the octahedral network determines more compact structures, with shorter B-O distances and narrower B-O-B angles in the proposed AB2O6 defect pyrochlore structure.Fil: Mayer, Sergio Federico. Instituto de Ciencia de Materiales de Madrid; España. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Falcon, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Fernández Díaz, María Teresa. Institut Laue Langevin; FranciaFil: Alonso, José Antonio. Instituto de Ciencia de Materiales de Madrid; EspañaMDPI AG2018-10-20info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/93570Mayer, Sergio Federico; Falcon, Horacio; Fernández Díaz, María Teresa; Alonso, José Antonio; The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data; MDPI AG; Crystals; 8; 10; 20-10-2018; 1-112073-43522073-4352CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.mdpi.com/2073-4352/8/10/368info:eu-repo/semantics/altIdentifier/doi/10.3390/cryst8100368info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:26:30Zoai:ri.conicet.gov.ar:11336/93570instacron: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 15:26:30.837CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
title The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
spellingShingle The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
Mayer, Sergio Federico
AB2O6
KNBTEO6
KNBWO6
KSBWO6
NEUTRON POWDER DIFFRACTION
PYROCHLORES
RIETVELD
title_short The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
title_full The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
title_fullStr The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
title_full_unstemmed The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
title_sort The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data
dc.creator.none.fl_str_mv Mayer, Sergio Federico
Falcon, Horacio
Fernández Díaz, María Teresa
Alonso, José Antonio
author Mayer, Sergio Federico
author_facet Mayer, Sergio Federico
Falcon, Horacio
Fernández Díaz, María Teresa
Alonso, José Antonio
author_role author
author2 Falcon, Horacio
Fernández Díaz, María Teresa
Alonso, José Antonio
author2_role author
author
author
dc.subject.none.fl_str_mv AB2O6
KNBTEO6
KNBWO6
KSBWO6
NEUTRON POWDER DIFFRACTION
PYROCHLORES
RIETVELD
topic AB2O6
KNBTEO6
KNBWO6
KSBWO6
NEUTRON POWDER DIFFRACTION
PYROCHLORES
RIETVELD
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Three defect pyrochlores KNbWO6·xH2O, KNbTeO6 and KSbWO6 were synthesized by solid state reaction at 750 °C, from stoichiometric mixtures of K2C2O4, Sb2O3, Nb2O5, WO3 and 20% excess TeO2. A neutron powder diffraction (NPD) data analysis allowed unveiling some structural features. They are all defined in the cubic (Formula Presented) space group symmetry, with α = 10.5068(1) Å, 10.2466(1) Å and 10.2377(1) Å, respectively. Difference Fourier synthesis for KNbWO6·xH2O clearly showed the presence of crystallization water, with extra O’ oxygen and H+ atoms that were located from NPD data. These O’ oxygen atoms are placed at 32e Wyckoff sites, conforming a K2O’ sublattice interpenetrated with the covalent framework constituted by (Nb,W)O6 octahedra. The H+ ions coordinate the O’ atoms at partially occupied 96g Wyckoff sites while K+ ions shift also along 32e sites, but closer to the 16c special site (0,0,0). By contrast, extra H2O molecules are absent in the other two pyrochlores: in KNbTeO6 and KSbWO6 K+ ions are shifted along 32e (x,x,x) sites further away from the origin than for the previous material, and the higher covalency of the octahedral network determines more compact structures, with shorter B-O distances and narrower B-O-B angles in the proposed AB2O6 defect pyrochlore structure.
Fil: Mayer, Sergio Federico. Instituto de Ciencia de Materiales de Madrid; España. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina
Fil: Falcon, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; Argentina
Fil: Fernández Díaz, María Teresa. Institut Laue Langevin; Francia
Fil: Alonso, José Antonio. Instituto de Ciencia de Materiales de Madrid; España
description Three defect pyrochlores KNbWO6·xH2O, KNbTeO6 and KSbWO6 were synthesized by solid state reaction at 750 °C, from stoichiometric mixtures of K2C2O4, Sb2O3, Nb2O5, WO3 and 20% excess TeO2. A neutron powder diffraction (NPD) data analysis allowed unveiling some structural features. They are all defined in the cubic (Formula Presented) space group symmetry, with α = 10.5068(1) Å, 10.2466(1) Å and 10.2377(1) Å, respectively. Difference Fourier synthesis for KNbWO6·xH2O clearly showed the presence of crystallization water, with extra O’ oxygen and H+ atoms that were located from NPD data. These O’ oxygen atoms are placed at 32e Wyckoff sites, conforming a K2O’ sublattice interpenetrated with the covalent framework constituted by (Nb,W)O6 octahedra. The H+ ions coordinate the O’ atoms at partially occupied 96g Wyckoff sites while K+ ions shift also along 32e sites, but closer to the 16c special site (0,0,0). By contrast, extra H2O molecules are absent in the other two pyrochlores: in KNbTeO6 and KSbWO6 K+ ions are shifted along 32e (x,x,x) sites further away from the origin than for the previous material, and the higher covalency of the octahedral network determines more compact structures, with shorter B-O distances and narrower B-O-B angles in the proposed AB2O6 defect pyrochlore structure.
publishDate 2018
dc.date.none.fl_str_mv 2018-10-20
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/11336/93570
Mayer, Sergio Federico; Falcon, Horacio; Fernández Díaz, María Teresa; Alonso, José Antonio; The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data; MDPI AG; Crystals; 8; 10; 20-10-2018; 1-11
2073-4352
2073-4352
CONICET Digital
CONICET
url http://hdl.handle.net/11336/93570
identifier_str_mv Mayer, Sergio Federico; Falcon, Horacio; Fernández Díaz, María Teresa; Alonso, José Antonio; The crystal structure of defect KBB’O6 pyrochlores (B,B’: Nb,W,Sb,Te) revisited from neutron diffraction data; MDPI AG; Crystals; 8; 10; 20-10-2018; 1-11
2073-4352
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.mdpi.com/2073-4352/8/10/368
info:eu-repo/semantics/altIdentifier/doi/10.3390/cryst8100368
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv MDPI AG
publisher.none.fl_str_mv MDPI AG
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 13.221938

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