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RESEARCH PRODUCT
Oxidation of nanocrystalline aluminum by variable charge molecular dynamics
Sébastien GarruchetOlivier PolitanoVincent VignalAurélien PerronGurcan Aralsubject
Materials scienceDiffusionOxideA. metals A. oxides A. thin films D. diffusion D. microstructure02 engineering and technologyGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciences7. Clean energyNanocrystalline materialGrain sizeMolecular dynamicsCrystallinitychemistry.chemical_compoundCondensed Matter::Materials SciencechemistryChemical physics0103 physical sciencesAtomGeneral Materials ScienceThin film010306 general physics0210 nano-technologydescription
International audience; We investigate the oxidation of nanocrystalline aluminum surfaces using molecular dynamics (MD) simulations with the variable charge model that allows charge dynamically transfer among atoms. The interaction potential between atoms is described by the electrostatic plus (Es+) potential model, which is composed of an embedded atom method potential and an electrostatic term. The simulations were performed from 300 to 750K on polycrystalline samples with a mean grain size of 5 nanometers. We mainly focused on the effect of the temperature parameter on the oxidation kinetic. The results show that, beyond a first linear regime, the kinetics follow a direct logarithmic law (governed by diffusion process) and tend to a limiting value corresponding to a thickness of ~3nm. We also characterized at 600K the effects of an external applied strain on the microstructure and the chemical composition of the oxide films formed at the surface. In particular, we obtained a partially crystalline oxide films for all temperature and we noticed a strong correlation between the degree of crystallinity of the oxide film and the oxidation temperature.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-01-20 |