Adaptive-boost molecular dynamics simulation of carbon diffusion in iron
Name
Ishii-2012-Adaptive-boost molecular dynamics simulation of carbon diffusion in iron.pdf
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631.6 KB
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Checksum (MD5)
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Author(s)
Ishii, Akio
Ogata, Shigenobu
Kimizuka, Hajime
Li, Ju
Date Issued
February 2012
Journal
Physical Review B
Publisher
American Physical Society
Citation
Ishii, Akio et al. “Adaptive-boost Molecular Dynamics Simulation of Carbon Diffusion in Iron.” Physical Review B 85.6 (2012): [7 pages]. ©2012 American Physical Society.
Version
Final published version
Abstract
We have developed an accelerated molecular dynamics (MD) method to model atomic-scale rare events. In this method, a smooth histogram of collective variables is first estimated by canonical ensemble molecular dynamics calculations, and then a temperature-dependent boost potential is iteratively constructed to accelerate the MD simulation. This method not only allows us to observe the rare events but also to evaluate the profile of free energy and trial frequency along the reaction coordinate. We employed this method to study carbon diffusion in bcc iron and evaluated carbon's temperature-dependent diffusivity. The obtained diffusivities agree well with the experimental measurements. Even at low temperature for which, to the best of our knowledge, no experimental data are available, the diffusivity can be evaluated accurately. Additionally, we study carbon diffusion inside the edge dislocation core in bcc iron, and demonstrate the applicability of the method to rare events on a rugged free-energy surface.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevB.85.064303
