Dislocation nucleation and propagation during thin film deposition under compression

W. C. Liu, San-Qiang Shi, Hanchen Huang, C. H. Woo

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)

Abstract

In this paper, we study the nucleation of dislocations and their subsequent propagation, during thin film deposition, using the three-dimensional (3D) molecular dynamics (MD) method. Aiming to reveal the generic mechanisms, the case of tungsten on a substrate of the same material is investigated. The substrate is under uniaxial compression along the [1 1 1] direction, with the thermodynamically favored (0 1̄ 1) surface being horizontal. The simulation results indicate that the nucleation starts with a surface step where an atom is squeezed to the layer above, generating a half-dislocation loop at the surface. It may then either propagate into the film or become the bottom of a sessile dislocation loop. In the first case, the dislocation loop, having a Burgers vector 1/2[1 1̄ 1̄] on a (1 0 1) glide plane, propagates along the [1 1̄ 1̄] direction on the surface, and extends to about two atomic layers along the [1 1 1] direction. In the second case, the missing layer propagates along the [1 0 0] direction on the surface, extending to about four atomic layers along the [1 1 1] direction. In this case, the sessile dislocation has a Burgers vector 1/2[1̄ 1̄ 1̄] on the plane (0 1 1).
Original languageEnglish
Pages (from-to)155-165
Number of pages11
JournalComputational Materials Science
Volume23
Issue number1-4
DOIs
Publication statusPublished - 1 Apr 2002

Keywords

  • Dislocation nucleation
  • Dislocation propagation
  • Molecular dynamics
  • Thin films

ASJC Scopus subject areas

  • Computer Science(all)
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Physics and Astronomy(all)
  • Computational Mathematics

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