Normand Mousseau
Professeur de physique et directeur académique
de l'Institut de l'énergie Trottier

Mickaël Trochet

Étudiant au doctorat

Projet de recherche

  • Diffusion de défauts dans le silicium
  • Batteries lithium-ion
  • ART cinétique


Articles en collaboration

  • O. A. Restrepo, N. Mousseau, M. Trochet, F. El-Mellouhi, O. Bouhali, C. S. Becquart, Carbon diffusion paths and segregation at high-angle tilt grain boundaries in \ensuremath\alpha-Fe studied by using a kinetic activation-relation technique, Phys. Rev. B 97, 054309 (2018).

  • S. Mahmoud, M. Trochet, O. A. Restrepo, N. Mousseau, Study of point defects diffusion in nickel using kinetic activation-relaxation technique, Acta Materialia 144, 679-690 (2018).
    Résumé : Abstract Point defects play a central role in materials properties. Yet, details regarding their diffusion and aggregation are still largely lacking beyond the monomer and dimer. Using the kinetic Activation Relaxation Technique (k-ART), a recently proposed off-lattice kinetic Monte Carlo method, the energy landscape, kinetics and diffusion mechanisms of point defect in fcc nickel are characterized, providing an exhaustive picture of the motion of one to five vacancies and self-interstitials in this system. Starting with a comparison of the prediction of four empirical potentials — the embedded atom method (EAM), the original modified embedded atom method (MEAM1NN), the second nearest neighbor modified embedded atom method (MEAM2NN) and the Reactive Force Field (ReaxFF) —, it is shown that while both EAM and ReaxFF capture the right physics, EAM provides the overall best agreement with ab initio and molecular dynamics simulations and available experiments both for vacancies and interstitial defect energetics and kinetics. Extensive k-ART simulations using this potential provide complete details of the energy landscape associated with these defects, demonstrated a complex set of mechanisms available to both vacancies and self-interstitials even in a simple environment such as crystalline Ni. We find, in particular, that the diffusion barriers of both vacancies and interstitials do not change monotonically with the cluster size and that some clusters of vacancies diffuse more easily than single ones. As self-interstitial clusters grow, moreover, we show that the fast diffusion takes place from excited states but ground states can act as pinning centers, contrary to what could be expected.
    Mots-clés : Diffusion mechanisms, Energy landscape, Kinetic Activation Relaxation Technique, Nickel, Self-defect.

  • M. Trochet, N. Mousseau, Energy landscape and diffusion kinetics of lithiated silicon: A kinetic activation-relaxation technique study, Phys. Rev. B 96, 134118 (2017).
    Mots-clés : ARTc.

  • M. Trochet, A. Sauvé-Lacoursière, N. Mousseau, Algorithmic developments of the kinetic activation-relaxation technique: Accessing long-time kinetics of larger and more complex systems, The Journal of Chemical Physics 147, 152712 (2017).

  • 0scar A. Restrepo, N. Mousseau, F. El-Mellouhi, O. Bouhali, M. Trochet, C. S. Becquart, Diffusion properties of Fe–C systems studied by using kinetic activation–relaxation technique, Computational Materials Science 112, Part A, 96-106 (2016).
    Résumé : Diffusion of carbon in iron is associated with processes such as carburization and the production of steels. In this work, the kinetic activation–relaxation technique (k-ART) – an off-lattice self-learning kinetic Monte Carlo (KMC) algorithm – is used to study this phenomenon over long time scales. Coupling the open-ended ART nouveau technique to generate on-the-fly activated events and NAUTY, a topological classification for cataloging, k-ART reaches timescales that range from microseconds to seconds while fully taking into account long-range elastic effects and complex events, characterizing in details the energy landscape in a way that cannot be done with standard molecular dynamics (MD) or KMC. The diffusion mechanisms and pathways for one to four carbon interstitials, and a single vacancy coupled with one to several carbons are studied. In bulk Fe, k-ART predicts correctly the 0.815 eV barrier for a single C-interstitial as well as the stressed induced energy-barrier distribution around this value for 2 and 4 C interstitials. For vacancy–carbon complex, simulations recover the DFT-predicted ground state. K-ART also identifies a trapping mechanism for the vacancy through the formation of a dynamical complex, involving C and neighboring Fe atoms, characterized by hops over barriers ranging from ∼0.41 to ∼0.72 eV that correspond, at room temperature, to trapping time of hours. At high temperatures, this complex can be broken by crossing a 1.5 eV barrier, leading to a state ∼0.8 eV higher than the ground state, allowing diffusion of the vacancy. A less stable complex is formed when a second C is added, characterized by a large number of bound excited states that occupy two cells. It can be broken into a V–C complex and a single free C through a 1.11 eV barrier.
    Mots-clés : ARTc.

  • M. Trochet, L. K. Béland, P. Brommer, J. - F. Joly, N. Mousseau, Diffusion of point defects in crystalline silicon using the kinetic ART method, Phys. Rev. B 91, 224106 (2015).
    Mots-clés : ARTc.

  • N. Mousseau, P. Brommer, J. - F. Joly, L. K. Béland, F. El-Mellouhi, G. K. N'Tsouaglo, et al., Following atomistic kinetics on experimental timescales with the kinetic Activation-Relaxation Technique, Computational Materials Science 100, 111-123 (2015).
    Mots-clés : ARTc.
mardi 1er juillet 2014

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