Atomic-level simulations of misfit dislocation at the interface of Fe2O3/Al2O3 system

F. Gao, C. M. Wang, S. Maheswaran, S. Thevuthasan

    Research output: Contribution to journalConference article

    5 Citations (Scopus)

    Abstract

    When α-Fe2O3 thin films are deposited on α-Al2O3(0 0 0 1) substrates using oxygen plasma assisted molecular beam epitaxy, a periodic distribution of basal dislocations occurs due to lattice mismatch along the interfaces. High-resolution transmission electron microscopy shows, when observed from 〈1 1 2 0〉 zone axis, that these dislocations lie at the interface about 7.0 nm apart. Molecular-dynamics simulations were performed in order to understand the formation of misfit dislocations and the interface structural features in Fe2O3/Al2O3 system. It is found that the misfit dislocations are mainly formed in Al2O3 substrates with Burger's vector of 1/3〈1 1 2 0〉, and terminated at the interfaces, in consistent with experiments observed previously. These dislocations can dissociate into two partial dislocations with Burger's vectors of 1/3〈1 0 1 0〉 and 1/3〈0 1 1 0〉 by forming stacking faults on (0 0 0 1) planes. The core structures of the misfit dislocations in semicoherent interfaces are analyzed in detail, and the misfit dislocations have narrow cores in the plane of the interfaces.

    Original languageEnglish
    Pages (from-to)63-71
    Number of pages9
    JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
    Volume207
    Issue number1
    DOIs
    Publication statusPublished - 1 May 2003
    EventSymposium: Ion beam processing and modification of glasses and - St.Louis, Missouri, United States
    Duration: 28 Apr 20021 May 2002

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    Keywords

    • Computer simulation
    • Epitaxy
    • Interface
    • Misfit dislocation

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics
    • Instrumentation

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