Systematic study of short- and long-range correlations in RE3TaO7 weberite-type compounds by neutron total scattering and X-ray diffraction - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Journal of Materials Chemistry A Année : 2023

Systematic study of short- and long-range correlations in RE3TaO7 weberite-type compounds by neutron total scattering and X-ray diffraction

Résumé

The atomic structures of the lanthanide tantalates, Ln3TaO7, series (Ln = Pr, Tb, Dy, Ho, Tm, Yb) were systematically investigated using total scattering techniques. High-energy X-ray and neutron diffraction analysis revealed that the long-range structures can be grouped into three distinct families: (1) ordered Cmcm (Ln = Pr), (2) ordered Ccmm (Ln = Tb, Dy, Ho), and (3) disordered, defect-fluorite Fm[3 with combining macron]m (Ln = Ho, Tm, Yb). These findings help to clarify the symmetry discrepancy for the already reported long-range structures in the literature. The short-range analysis of neutron total scattering data via pair distribution functions reveals a high degree of structural heterogeneity across length scales for all compounds, with distinct local atomic arrangements that are not fully captured by the average, long-range structure. The short-range structures at the level of coordination polyhedra are better captured by a set of alternative non-centrosymmetric structural models: (1) C2cm, (2) C2221, and (3) C2mm. This establishes a short-range multiferroic character for weberite-type tantalates because ferroelectric interactions compete with magnetic correlations. These ferroelectric interactions are particularly pronounced for the disordered compounds Tm3TaO7 and Yb3TaO7. The structural differences among the three families are the result of changes in TaO6 polyhedral tilt (transition between families 1 and 2) and dipolar interactions of off-centered Ta cations (transition between families 2 and 3).
Fichier principal
Vignette du fichier
Gussev_JMCA_2023.pdf (5.67 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Licence : CC BY NC - Paternité - Pas d'utilisation commerciale

Dates et versions

hal-04061135 , version 1 (07-04-2023)

Identifiants

Citer

Igor Gussev, Eric O'Quinn, Matthew Tucker, Rodney Ewing, Cale Overstreet, et al.. Systematic study of short- and long-range correlations in RE3TaO7 weberite-type compounds by neutron total scattering and X-ray diffraction. Journal of Materials Chemistry A, inPress, ⟨10.1039/D3TA01042B⟩. ⟨hal-04061135⟩
21 Consultations
50 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More