Symmetry and twins in the monophosphate ...
Type de document :
Article dans une revue scientifique: Article original
PMID :
URL permanente :
Titre :
Symmetry and twins in the monophosphate tungsten bronze series (P02)4(W03)2m (2 < or = m < or = 14)
Auteur(s) :
Roussel, Pascal [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]
Labbe, P. [Auteur]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]
Groult, D. [Auteur]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]

Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]
Labbe, P. [Auteur]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]
Groult, D. [Auteur]
Laboratoire de cristallographie et sciences des matériaux [CRISMAT]
Titre de la revue :
Acta Crystallographica Section B : Structural Science [1968-2013]
Nom court de la revue :
Acta Crystallogr., B
Numéro :
56
Pagination :
377-91
Date de publication :
2000-06
ISSN :
1600-5740
Discipline(s) HAL :
Chimie
Résumé en anglais : [en]
Monophosphate tungsten bronze with pentagonal tunnels (PO2)4(WO3)2m are low-dimensional materials with charge density wave (CDW)-type electron instabilities. Two forms of the structure can thus be expected for all the ...
Lire la suite >Monophosphate tungsten bronze with pentagonal tunnels (PO2)4(WO3)2m are low-dimensional materials with charge density wave (CDW)-type electron instabilities. Two forms of the structure can thus be expected for all the members of the series: a low-temperature form (LT) corresponding to the CDW state and a high-temperature form (HT) corresponding to a normal metallic state. The HT form is described here for m = 9 and compared with that of the m = 5 and m = 7 counterparts. It is shown that a systematic twin phenomenon must be taken into account for HT members because of two possible configurations of the tilting mode of WO6 octahedra. The structure is also compared with that of m = 10, which exhibits the modulated CDW–LT form at room temperature. Owing to two possible polarization directions of the segments built of m WO6 octahedra, a twin phenomenon is also encountered in the LT forms. A review of all the structures known at present (m = 2, 4, 5, 6, 7, 8, 9, 10, 12) leads us to propose a structural law based on the building mode of WO6 octahedra in WO3-type slabs to explain the symmetry changes observed between even and odd members of the series.Lire moins >
Lire la suite >Monophosphate tungsten bronze with pentagonal tunnels (PO2)4(WO3)2m are low-dimensional materials with charge density wave (CDW)-type electron instabilities. Two forms of the structure can thus be expected for all the members of the series: a low-temperature form (LT) corresponding to the CDW state and a high-temperature form (HT) corresponding to a normal metallic state. The HT form is described here for m = 9 and compared with that of the m = 5 and m = 7 counterparts. It is shown that a systematic twin phenomenon must be taken into account for HT members because of two possible configurations of the tilting mode of WO6 octahedra. The structure is also compared with that of m = 10, which exhibits the modulated CDW–LT form at room temperature. Owing to two possible polarization directions of the segments built of m WO6 octahedra, a twin phenomenon is also encountered in the LT forms. A review of all the structures known at present (m = 2, 4, 5, 6, 7, 8, 9, 10, 12) leads us to propose a structural law based on the building mode of WO6 octahedra in WO3-type slabs to explain the symmetry changes observed between even and odd members of the series.Lire moins >
Langue :
Anglais
Audience :
Internationale
Vulgarisation :
Non
Établissement(s) :
Université de Lille
CNRS
Centrale Lille
ENSCL
Univ. Artois
CNRS
Centrale Lille
ENSCL
Univ. Artois
Collections :
Équipe(s) de recherche :
Matériaux inorganiques, structures, systèmes et propriétés (MISSP)
Date de dépôt :
2023-05-30T18:46:16Z
2024-04-26T09:11:34Z
2024-04-26T09:11:34Z