Influence of growth rate on the epitaxial orientation and crystalline quality of CeO2 thin films grown on Al2O3(0001)

M. I. Nandasiri, P. Nachimuthu, T. Varga, V. Shutthanandan, W. Jiang, Satyanarayana V.N.T. Kuchibhatla, S. Thevuthasan, S. Seal, A. Kayani

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    Abstract

    Growth rate-induced epitaxial orientations and crystalline quality of CeO2 thin films grown on Al2O3(0001) by oxygen plasma-assisted molecular beam epitaxy were studied using in situ and ex situ characterization techniques. CeO2 grows as three-dimensional (3D) islands and two-dimensional layers at growth rates of 1-7 Å/min and (9 Å/min, respectively. The formation of epitaxial CeO2(100) and CeO2(111) thin films occurs at growth rates of 1 Å/min and (9 Å/min, respectively. Glancing-incidence x-ray diffraction measurements have shown that the films grown at intermediate growth rates (2-7 Å/min) consist of polycrystalline CeO2 along with CeO2(100). The thin film grown at 1 Å/min exhibits six in-plane domains, characteristic of well-aligned CeO2(100) crystallites. The content of the poorly aligned CeO2(100) crystallites increases with increasing growth rate from 2 to 7 Å/min, and three out of six in-plane domains gradually decrease and eventually disappear, as confirmed by XRD pole figures. At growth rates (9 Å/min, CeO2(111) film with single in-plane domain was identified. The formation of CeO2(100) 3D islands at growth rates of 1-7 Å/min is a kinetically driven process unlike at growth rates (9 Å/min which result in an energetically and thermodynamically more stable CeO2(111) surface.

    Original languageEnglish
    Article number013525
    JournalJournal of Applied Physics
    Volume109
    Issue number1
    DOIs
    Publication statusPublished - 1 Jan 2011

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    ASJC Scopus subject areas

    • Physics and Astronomy(all)

    Cite this

    Nandasiri, M. I., Nachimuthu, P., Varga, T., Shutthanandan, V., Jiang, W., Kuchibhatla, S. V. N. T., Thevuthasan, S., Seal, S., & Kayani, A. (2011). Influence of growth rate on the epitaxial orientation and crystalline quality of CeO2 thin films grown on Al2O3(0001). Journal of Applied Physics, 109(1), [013525]. https://doi.org/10.1063/1.3525558