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

    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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