Titre :

Systematic theoretical study of [001] symmetric tilt grain boundaries in MgO from 0 to 120 GPa

Auteur(s) :

Hirel, Pierre [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Moladje, Gabriel Franck Bouobda [Auteur]
Carrez, Philippe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Cordier, Patrick [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Titre de la revue :

Physics and chemistry of minerals

Nom court de la revue :

Phys Chem Minerals

Numéro :

46

Pagination :

37-49

Éditeur :

Springer Nature

Date de publication :

2018-07-04

Discipline(s) HAL :

Chimie

Résumé en anglais : [en]

The properties of [001] symmetric tilt grain boundaries (STGBs) in magnesium oxide (MgO) are investigated systematically with atomic-scale simulations. Their formation energies, atomic structures, and excess volumes are ...
Lire la suite >The properties of [001] symmetric tilt grain boundaries (STGBs) in magnesium oxide (MgO) are investigated systematically with atomic-scale simulations. Their formation energies, atomic structures, and excess volumes are computed. STGBs are found to prefer a symmetric configuration, except for tilt angles larger than 67.4°, where the decomposition of the STGBs into ½[110] dislocations is preferred. Then, the effects of pressure are investigated from 30 up to 120 GPa, a pressure range relevant to the Earth’s lower mantle. Pressure is found to change the atomic configuration of all investigated GBs, sometimes several times as pressure increases. We also find that these changes are irreversible, the GBs retaining their high-pressure configuration even after pressure is released. Implications for the deformation of ferropericlase in the conditions of the Earth’s lower mantle are discussed.Lire moins >

Langue :

Anglais

Audience :

Internationale

Projet Européen :

MULTISCALE MODELLING OF THE RHEOLOGY OF MANTLE MINERALS

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Plasticité

Date de dépôt :

2019-04-03T12:42:53Z
2019-04-05T12:01:56Z