Synthesis, crystal structures and photoluminescence properties of new oxyborates, Mg5NbO3(BO3)3 and Mg5TaO3(BO3)3, with novel warwickite-type superstructures

Tetsuya Kawano, Hisanori Yamane

    Research output: Contribution to journalArticlepeer-review

    4 Citations (Scopus)


    Single crystals of new oxyborates, Mg5NbO3(BO 3)3 and Mg5TaO3(BO3) 3, were prepared at 1370 °C in air using B2O 3 as a flux. They were colorless and transparent with block shapes. X-ray diffraction analysis of the single crystals revealed Mg 5NbO3(BO3)3 and Mg 5TaO3(BO3)3 to be isostructural. The X-ray diffraction reflections were indexed to the orthorhombic Pnma (No. 62) system with a=9.3682(3) Å, b=9.4344(2) Å, c=9.3379(3) Å and Z=4 for Mg5NbO3(BO3)3 and a=9.3702(3) Å, b=9.4415(3) Å, c=9.3301(2) Å and Z=4 for Mg5TaO3(BO3)3. The crystal structures of Mg5NbO3(BO3)3 and Mg5TaO3(BO3)3 are novel warwickite-type superstructures having ordered arrangements of Mg and Nb/Ta atoms. Polycrystals of Mg5NbO3(BO3)3 prepared by solid state reaction at 1200 °C in air showed broad blue-to-green emission with a peak wavelength of 470 nm under 270 nm ultraviolet excitation at room temperature.

    Original languageEnglish
    Pages (from-to)2466-2471
    Number of pages6
    JournalJournal of Solid State Chemistry
    Issue number9
    Publication statusPublished - 2011 Sep


    • Crystal structure analysis
    • Magnesium niobium (V) oxyborate
    • Magnesium tantalum (V) oxyborate
    • Photoluminescence
    • Synthesis
    • X-ray diffraction

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Ceramics and Composites
    • Condensed Matter Physics
    • Physical and Theoretical Chemistry
    • Inorganic Chemistry
    • Materials Chemistry


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