Core structure and dissociation energetics of basal edge dislocation in α-Al2O3: A combined atomistic simulation and transmission electron microscopy analysis

Kenji Tsuruta, Eita Tochigi, Yuki Kezuka, Kazuaki Takata, Naoya Shibata, Atsutomo Nakamura, Yuichi Ikuhara

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Using large-scale molecular dynamics (MD) simulations, we investigate the energetics and local structures/stresses of partial dislocations, 1/3〈011̄0〉 and 1/3〈101̄0〉, dissociated from the 1/3〈112̄0〉 perfect basal edge dislocation in α-Al 2O3. The validity of the model adopted in the simulation is confirmed by comparing with theoretical stress/strain distributions and with those experimentally obtained from a high-resolution transmission electron microscopy (HRTEM) observation. Partial dislocation pairs have a stable inter-core distance (∼2 nm), which is also a phenomenon that is observed in the HRTEM experiments. The distance between the partials can be explained quantitatively by the balance between an elastic core-core repulsion and an effective attractive force against the extension of stacking faults (SFs). A comparison is made for two types of core structures of partial dislocations: a pair of partials with Al-terminated/O-terminated extra-half planes and that with Al-/Al-terminated ones. The overall tendency of the inter-core interaction and the equilibrium distances are the same in both cases, whereas the Al-O-terminated pair is slightly favourable in energy at the equilibrium distance. A residual shear stress on the SF plane is observed in the MD results, which can be attributed to local atomic structure in the SF.

Original languageEnglish
Pages (from-to)76-84
Number of pages9
JournalActa Materialia
Volume65
DOIs
Publication statusPublished - Feb 15 2014

Keywords

  • Alumina
  • Dislocation
  • Molecular dynamics
  • Stacking fault
  • TEM

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Core structure and dissociation energetics of basal edge dislocation in α-Al<sub>2</sub>O<sub>3</sub>: A combined atomistic simulation and transmission electron microscopy analysis'. Together they form a unique fingerprint.

Cite this