Diffusion mechanisms in Cu grain boundaries

dc.contributorVirginia Techen
dc.contributor.authorSorensen, M. R.en
dc.contributor.authorMishin, Y.en
dc.contributor.authorVoter, A. F.en
dc.contributor.departmentMaterials Science and Engineering (MSE)en
dc.date.accessed2014-04-23en
dc.date.accessioned2014-05-07T15:36:53Zen
dc.date.available2014-05-07T15:36:53Zen
dc.date.issued2000-08-01en
dc.description.abstractWe 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.en
dc.description.sponsorshipU.S. Department of Energy under Contracts No. W-7405-ENG-36, DE-FG02-99ER45769en
dc.format.mimetypeapplication/pdfen
dc.identifier.citationSorensen, M. R.; Mishin, Y.; Voter, A. F., "Diffusion mechanisms in Cu grain boundaries," Phys. Rev. B 62, 3658 DOI: http://dx.doi.org/10.1103/PhysRevB.62.3658en
dc.identifier.doihttps://doi.org/10.1103/PhysRevB.62.3658en
dc.identifier.issn0163-1829en
dc.identifier.urihttp://hdl.handle.net/10919/47825en
dc.identifier.urlhttp://journals.aps.org/prb/abstract/10.1103/PhysRevB.62.3658en
dc.language.isoen_USen
dc.publisherAmerican Physical Societyen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject001 tilt boundariesen
dc.subjectMolecular dynamicsen
dc.subjectSelf-diffusionen
dc.subjectComputer simulationen
dc.subjectPoint defectsen
dc.subjectAu/ag systemen
dc.subjectMigrationen
dc.subjectSurfacesen
dc.subjectKineticsen
dc.subjectMobilityen
dc.subjectPhysicsen
dc.subjectCondensed matteren
dc.titleDiffusion mechanisms in Cu grain boundariesen
dc.title.serialPhysical Review Ben
dc.typeArticle - Refereeden
dc.type.dcmitypeTexten
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