Titre :

Diffusion mechanism of bound Schottky defect in magnesium oxide

Auteur(s) :

Mahmoud, Sami [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Carrez, Philippe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Landeiro Dos Reis, Marie [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Mousseau, Normand [Auteur]
Département de Physique [Montréal]
Regroupement Québécois sur les Matériaux de Pointe [RQMP]
Cordier, Patrick [Auteur]
Institut universitaire de France [IUF]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Titre de la revue :

Physical Review Materials

Nom court de la revue :

Phys. Rev. Materials

Numéro :

5

Pagination :

033609

Éditeur :

American Physical Society (APS)

Date de publication :

2021-03-25

ISSN :

2475-9953

Mot(s)-clé(s) en anglais :

Point defects
Self-diffusion

Discipline(s) HAL :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Planète et Univers [physics]/Sciences de la Terre

Résumé en anglais : [en]

In simple ionic crystals, intrinsic point defects must satisfy electrical neutrality and exist as Schottky defects. In magnesium oxide (MgO), a Schottky defect is then a combination of anionic and cationic vacancies. Since ...
Lire la suite >In simple ionic crystals, intrinsic point defects must satisfy electrical neutrality and exist as Schottky defects. In magnesium oxide (MgO), a Schottky defect is then a combination of anionic and cationic vacancies. Since vacancies are charged, the stable configuration of the Schottky defect corresponds to a bound pair of vacancies of opposite signs. In this study, we investigate the kinetics of formation and migration of such a bound pair on long timescales reaching in some cases thousands of seconds using the kinetic activation-relaxation technique, an off-lattice kinetic Monte Carlo method with an event catalog built on-the-fly during static molecular simulations. We show that the diffusion of this bound Schottky defect involves the migration of vacancies bounded to the first and third neighbor sites of the crystal structure with an apparent migration energy which cannot be inferred from the migration energies expected from isolated defects. Overall, this study gives insights and constraints on the oxygen diffusion mechanism reported experimentally in high-purity MgO samples.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Projet Européen :

Rheology of Earth materials: closing the gap between TIMEscales in the laboratory and in the MANtle

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Plasticité

Date de dépôt :

2021-03-26T10:09:12Z
2021-03-26T15:45:00Z