Crystallography and structural evolution of LiNbO3 and LiNb1-xTaxO3 films on sapphire prepared by high-rate thermal plasma spray chemical vapor deposition

D. V. Shtansky, S. A. Kulinich, K. Terashima, T. Yoshida, Y. Ikuhara

    研究成果: Article査読

    11 被引用数 (Scopus)


    The structure and the crystallography of lithium niobate and lithium niobate-tantalate thin films (0.2-1.0 μm in thickness) with the tantalum composition range of 0 ≤ x ≤ 0.5 grown on (0001) sapphire substrate by thermal plasma spray chemical vapor deposition have been studied by means of cross-sectional high-resolution transmission electron microscopy and x-ray diffraction. The tantalum composition in the films shows a minor effect on the rocking curve full width at half maximum values. The narrowest rocking curve width was obtained for the LiNb0.5Ta0.5O3 film to be as low as 0.25° λ. The films are under compressive strain along the c direction; c- and a-axis lattice parameters are correspondingly smaller and higher than those of the bulk single crystal. Under optimized growth conditions, the LiNbO3 and LiNb1-xTaxO3 films are 97% c-axis oriented. The film out-of-plane orientation changes from the [0001] to the [0112] direction by either decreasing the growth rate or increasing the substrate temperature. Particular attention has been paid to the orientation of individual grains in the partly c-axis-oriented films. The results demonstrate that their orientations are not random and specific orientation relationships are preferred for the film nucleation. The surface of as-received sapphire substrate reveals polishing defects with the well-defined surface ledges of 1-2 nm in height with smooth terraces of 25 nm in width. In the case of columnar growth, the terrace width becomes a limiting factor controlling the lateral crystallite size in the film. Finally, the film growth mechanism is discussed.

    ジャーナルJournal of Materials Research
    出版ステータスPublished - 2001 8

    ASJC Scopus subject areas

    • 材料科学(全般)
    • 凝縮系物理学
    • 材料力学
    • 機械工学


    「Crystallography and structural evolution of LiNbO<sub>3</sub> and LiNb<sub>1-x</sub>Ta<sub>x</sub>O<sub>3</sub> films on sapphire prepared by high-rate thermal plasma spray chemical vapor deposition」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。