Self-interstitial transport in vanadium

Luis A. Zepeda-Ruiz, Jörg Rottler, Brian D. Wirth, Roberto Car, David J. Srolovitz

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

We study the diffusion of self-interstitial atoms (SIAs) and SIA clusters in vanadium via molecular dynamics simulations with an improved Finnis-Sinclair potential (fit to first-principles results for SIA structure and energetics). The present results demonstrate that single SIAs exist in a 〈1 1 1〉-dumbbell configuration and migrate easily along 〈1 1 1〉 directions. Changes of direction through rotations into other 〈1 1 1〉 directions are infrequent at low temperatures, but become prominent at higher temperatures, thereby changing the migration path from predominantly one-dimensional to almost isotropically three-dimensional. SIA clusters (i.e., clusters of 〈1 1 1〉-dumbbells) can be described as perfect prismatic dislocation loops with Burgers vector and habit planes of 1/2〈1 1 1〉{2 2 0} that migrate only along their glide cylinder. SIA clusters also migrate along 〈1 1 1〉-directions, but do not rotate. Both single SIAs and their clusters exhibit a highly non-Arrhenius diffusivity, which originates from a combination of a temperature dependent correlation factor and the presence of very low migration barriers. At low temperature, the diffusion is approximately Arrhenius, while above room temperature, the diffusivity is a linear function of temperature. A simple model is proposed to describe these diffusion regimes and the transition between them.

Original languageEnglish (US)
Pages (from-to)1985-1994
Number of pages10
JournalActa Materialia
Volume53
Issue number7
DOIs
StatePublished - Apr 1 2005

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Keywords

  • Diffusion
  • Dislocation loop
  • Interstitial
  • Molecular dynamics simulation
  • Vanadium

Fingerprint Dive into the research topics of 'Self-interstitial transport in vanadium'. Together they form a unique fingerprint.

  • Cite this

    Zepeda-Ruiz, L. A., Rottler, J., Wirth, B. D., Car, R., & Srolovitz, D. J. (2005). Self-interstitial transport in vanadium. Acta Materialia, 53(7), 1985-1994. https://doi.org/10.1016/j.actamat.2005.01.010