Atomic structure, energetics, and chemical bonding of y doped Σ13 grain boundaries in α-Al2O3

Shinya Azuma, Naoya Shibata, Teruyasu Mizoguchi, Scott D. Findlay, Kaoru Nakamura, Yuichi Ikuhara

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

The atomic structure, energetics and chemical bonding state of pristine and Y doped Σ13, (10 4) grain boundaries in α-Al2O 3 were investigated by aberration-corrected Z-contrast scanning transmission electron microscopy combined with first-principles calculations. Combining observations from two orthogonal directions parallel to the grain boundary plane, we found that Y atoms segregate into specific atomic sites and form two-dimensionally ordered structure. We performed first-principles calculations to estimate stable atomic sites for Y segregation, and it was found that the calculation results are in good agreement with the experimental results. Local chemical bonding states at the core of the boundary were investigated by a first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method, and Y atoms and neighboring O atoms were found to evince strong ionic character while O-Al back bonds evince strong covalent character.

Original languageEnglish
Pages (from-to)1158-1171
Number of pages14
JournalPhilosophical Magazine
Volume93
Issue number10-12
DOIs
Publication statusPublished - 2013 Apr 1
Externally publishedYes

Keywords

  • HAADF STEM
  • Y doping
  • alumina
  • chemical bonding character
  • first-principles calculations
  • grain boundary
  • segregation

ASJC Scopus subject areas

  • Condensed Matter Physics

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