Title :

Compressibility of structural modulation waves in the chain compounds BaCoX2O7 (X = As, P): a powder study

Author(s) :

Das, Ranjana R. [Auteur]
Leclercq, Bastien [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Bouvier, Pierre [Auteur]
Arevalo Lopez, Angel [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Goujon, Céline [Auteur]
Itié, Jean-Paul [Auteur]
Polian, Alain [Auteur]
Mentre, Olivier [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Colin, Claire V. [Auteur]

Journal title :

Acta Crystallographica Section B : Structural Science, Crystal Engineering and Materials [2014-...]

Abbreviated title :

Acta Crystallogr B Struct Sci Cryst Eng Mater

Volume number :

78

Pages :

162-171

Publisher :

International Union of Crystallography

Publication date :

2022-04-17

ISSN :

2052-5206

English keyword(s) :

DFT-relaxed structural models
high-pressure X-ray diffraction
high-pressure Raman spectroscopy
first-order structural phase transition
incommensurate structural modulation

HAL domain(s) :

Chimie/Cristallographie
Chimie/Chimie inorganique

English abstract : [en]

BaCoX2O7 (X = As, P) are built on magnetic 1D units in which strong aperiodic undulations originate from incommensurate structural modulations with large atomic displacive amplitudes perpendicular to the chain directions, ...
Show more >BaCoX2O7 (X = As, P) are built on magnetic 1D units in which strong aperiodic undulations originate from incommensurate structural modulations with large atomic displacive amplitudes perpendicular to the chain directions, resulting in very unique multiferroic properties. High-pressure structural and vibrational properties of both compounds have been investigated by synchrotron X-ray powder diffraction and Raman spectroscopy at room temperature and combined with density functional calculations. A structural phase transition is observed at 1.8 GPa and 6.8 GPa in BaCoAs2O7 and BaCoP2O7, respectively. Sharp jumps are observed in their unit-cell volumes and in Raman mode frequencies, thus confirming the first-order nature of their phase transition. These transitions involve the disappearance of the modulation from the ambient-pressure polymorph with clear spectroscopic fingerprints, such as reduction of the number of Raman modes and change of shape on some peaks. The relation between the evolution of the Raman modes along with the structure are presented and supported by density functional theory structural relaxations.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

ANR Project :

Couplages Magnéto-Electriques exacerbés dans des matériaux à unités ferromagnétiques

Administrative institution(s) :

Université de Lille
CNRS
Centrale Lille
ENSCL
Univ. Artois

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Matériaux inorganiques, structures, systèmes et propriétés (MISSP)

Submission date :

2023-05-30T15:19:31Z
2023-06-21T09:19:10Z