2021 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 15 - Sep 19, 2021Online
2021 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 15 - Sep 19, 2021Online
[R2-02]Chemical formula, crystal structure and dielectric properties of swedenborgite
*Hidetomo Hongu1, Akira Yoshiasa1, Mayu Yoshihara1, Ginga Kitahara1, Kohei Unoki1, Makoto Tokuda2, Kazumasa Sugiyama2, Koichi Momma3, Ritsuro Miyawaki3(1. Kumamoto Univ., 2. Tohoku Univ., 3. National Museum of Nature and Science)
Keywords:
swedenborgite,bromellite,chemical formula,structure refinement,dielectric properties
In this study, we determined the chemical formula of swedenborgite using SEM/EDS and Sb XAFS analysis. The chemical formula of swedenborgite can be expressed as (Na1-xCax)Be4-0.5xSbO7 (x ≦ 0.05). The crystal structure of swedenborgite [space group P63mc, a = 5.4402(10), c = 8.8690(9) Å, Z = 2] was analyzed using single-crystal X-ray diffraction method and was refined to the R1 value of 0.012 for 1573 unique reflections. Considering the arrangement of atoms in the structure, swedenborgite has strong dielectric properties.