• Log in
    View Item 
    •   VTechWorks Home
    • College of Engineering (COE)
    • Department of Materials Science and Engineering (MSE)
    • Research Articles, Materials Science and Engineering (MSE)
    • View Item
    •   VTechWorks Home
    • College of Engineering (COE)
    • Department of Materials Science and Engineering (MSE)
    • Research Articles, Materials Science and Engineering (MSE)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Diffusion mechanisms in Cu grain boundaries

    Thumbnail
    View/Open
    Main article (231.4Kb)
    Downloads: 369
    Date
    2000-08-01
    Author
    Sorensen, M. R.
    Mishin, Y.
    Voter, A. F.
    Metadata
    Show full item record
    Abstract
    We investigate atomic mechanisms of grain boundary (GB) diffusion by combining molecular dynamics (MD), molecular statics, the harmonic approximation to atomic vibrations, and kinetic Monte Carlo (KMC) simulations. The most important aspects of this approach are the basin-constrained implementation of MD and an automated location of transition states using the nudged elastic band method. We study two Sigma=5 [001] symmetric tilt GB's in Cu, with atomic interactions described by an embedded-atom potential. Our simulations demonstrate that GB's support both vacancies and interstitials, and that vacancies can show interesting effects such as delocalization and instability at certain GB sites. Besides simple vacancy-atom exchanges, vacancies move by "long jumps" involving a concerted motion of two atoms. Interstitials move through concerted displacements of two or more atoms. More complex mechanisms (such as ring processes) involving larger groups of atoms have also been found. The obtained point defect formation energies and entropies, as well as their migration rate constants calculated within harmonic transition state theory, are used as input to KMC simulations of GB diffusion. The simulations show that GB diffusion can be dominated by either vacancy or interstitial-related mechanisms depending on the GB structure. The KMC simulations also reveal interesting effects such as temperature-dependent correlation factors and the trapping effect. Using the same simulation approach we study mechanisms of point defect generation in GB's and show that such mechanisms also involve collective transitions.
    URI
    http://hdl.handle.net/10919/47825
    Collections
    • Research Articles, Materials Science and Engineering (MSE) [319]

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us
     

     

    VTechWorks

    AboutPoliciesHelp

    Browse

    All of VTechWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Log inRegister

    Statistics

    View Usage Statistics

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us