Title :

Diffusion mechanisms for spinel ferrite NiFe2O4 by using kinetic activation–relaxation technique

Author(s) :

Restrepo, Oscar A. [Auteur]
Universidad de Antioquia = University of Antioquia [Medellín, Colombia]
Becquart, Charlotte [Auteur]
1002334|||Unité Matériaux et Transformations - UMR 8207 [UMET] (VALID)
Mousseau, Normand [Auteur]
Regroupement Québécois sur les Matériaux de Pointe [RQMP]

Journal title :

The Journal of Chemical Physics

Volume number :

161

Pages :

094307

Publisher :

AIP Publishing

Publication date :

2024-09-07

ISSN :

0021-9606

HAL domain(s) :

Chimie/Matériaux
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]

English abstract : [en]

Mass transport in bulk spinel ferrites NiFe2O4 is studied computationally using the kinetic activation–relaxation technique (k-ART), an off-lattice kinetic Monte Carlo algorithm. Diffusion mechanisms—difficult to observe ...
Show more >Mass transport in bulk spinel ferrites NiFe2O4 is studied computationally using the kinetic activation–relaxation technique (k-ART), an off-lattice kinetic Monte Carlo algorithm. Diffusion mechanisms—difficult to observe with molecular dynamics—are described by k-ART. Point defects are assumed to be responsible for ionic diffusion; thus, both cation and anion defects are investigated. This work focuses on vacancies and interstitials by comparing their properties with two Buckingham potential parameterizations: one with nominal charges and the other with partial charges. Both potentials are corrected at short distances, thus allowing interstitial diffusion and avoiding the catastrophic infinite energies appearing with Buckingham at short distances. The energy landscape along different pathways is described in detail. Both potentials predict the same mechanisms but different migration energies. Mechanisms by which a normal spinel is transformed to an inverse spinel via cation diffusion are unveiled, and diffusion coefficients are predicted. We find that interstitial Ni diffusion involves the movement of two Ni ions and that O interstitials trigger a collective diffusion of O ions, while an O vacancy diffuses by an O ion moving to the center of a cuboctahedron.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Métallurgie Physique et Génie des Matériaux

Submission date :

2024-09-09T08:48:38Z
2024-09-10T11:03:59Z