A curved pathway for oxygen interstitial diffusion in aluminum

Journal Article · Fri Dec 01 00:00:00 EST 2017 · Computational Materials Science

DOI:https://doi.org/10.1016/j.commatsci.2017.08.014· OSTI ID:1462699

Ross, A. J. ^[1]; Fang, H. Z. ^[1]; Shang, S. L. ^[1]; Lindwall, G. ^[1]; Liu, Z. K. ^[1]

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1. The Pennsylvania State University, University Park, PA (United States). Department of Materials Science and Engineering

The diffusion of interstitial oxygen (O) in fcc aluminum (Al) has been studied using first-principles andthe diffusion coefficient has been calculated. Whereas interstitial atoms in fcc systems are typically foundto hop directly between interstitial centres, the diffusion pathway for interstitial O in fcc Al was calcu-lated to have a curved minimum energy pathway with an energy barrier of 0.95 eV. The barrier was foundto be off-centre of a neighboring octahedral site. Also unlike the majority of fcc metals, O prefers to sit inthe tetrahedral interstitial site as opposed to the octahedral site. The calculated O diffusion coefficient ison the same order of magnitude of the diffusion coefficient of O in other fcc metals. The preferred inter-stitial site, diffusion pathway and vacancy binding energy were found to be related to the bond length ofO with neighboring Al atoms.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• DOE Contract Number: AC02-05CH11231; FE00400
• OSTI ID: 1462699
• Journal Information: Computational Materials Science, Vol. 140, Issue C; ISSN 0927-0256
• Publisher: Elsevier
• Country of Publication: United States
• Language: English