Title :

Diffusion mechanisms of C in 100, 110 and 111 Fe surfaces studied using kinetic activation-relaxation technique

Author(s) :

Restrepo, Oscar A. [Auteur]
Texas A&M University at Qatar
Université de Montréal [UdeM]
Becquart, Charlotte [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
El-Mellouhi, Fedwa [Auteur]
Qatar Environment and Energy Research Institute [QEERI]
Bouhali, Othmane [Auteur]
Texas A&M University at Qatar
Mousseau, Normand [Auteur]
Département de Physique [Montréal]
Regroupement Québécois sur les Matériaux de Pointe [RQMP]

Journal title :

Acta Materialia

Volume number :

136

Pages :

303-314

Publication date :

2017-09-01

HAL domain(s) :

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

English abstract : [en]

The physics of Fe-C surface interactions is of fundamental importance to phenomena such as corrosion, catalysis, synthesis of graphene, new steels, etc. To better understand this question, we perform an extensive ...
Show more >The physics of Fe-C surface interactions is of fundamental importance to phenomena such as corrosion, catalysis, synthesis of graphene, new steels, etc. To better understand this question, we perform an extensive characterization of the energy landscape for carbon diffusion from bulk to surfaces for bcc iron at low C concentration. C diffusion mechanisms over the three main Fe-surfaces – (100), (110) and (111) – are studied computationally using the kinetic activation-relaxation technique (k-ART), an off-lattice kinetic Monte Carlo algorithm. Migration and adsorption energies on surfaces as well as absorption energies into the subsurfaces are predicted and then compared to density functional theory (DFT) and experiment. The energy landscape along C-diffusion pathways from bulk to surface is constructed allowing a more extensive characterization of the diffusion pathways between surface and subsurface. In particular, effective migration energies from (100), (110) and (111) surfaces, to the bulk octahedral site are found to be around ∼1.6 eV, ∼1.2 eV and ∼1.3 eV respectively suggesting that C insertion into the bulk cannot take place in pure crystalline Fe, irrespective of the exposed surface.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Métallurgie Physique et Génie des Matériaux

Submission date :

2019-05-16T17:20:51Z
2021-06-17T15:13:45Z
2024-09-03T11:25:23Z