Postperovskite phase transition of ZnGeO3: Comparative crystal chemistry of postperovskite phase transition from germanate perovskites

Hitoshi Yusa, Taku Tsuchiya, Masaki Akaogi, Hiroshi Kojitani, Daisuke Yamazaki, Naohisa Hirao, Yasuo Ohishi, Takumi Kikegawa

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)

    Abstract

    The postperovskite phase of ZnGeO3 was confirmed by laser heating experiments of the perovskite phase under 110-130 GPa at high temperature. Ab initio calculations indicated that the phase transition occurs at 133 GPa at 0 K. This postperovskite transition pressure is significantly higher than those reported for other germanates, such as MnGeO3 and MgGeO3. The comparative crystal chemistry of the perovskite-to-postperovskite transition suggests that a relatively elongated b-axis in the low-pressure range resulted in the delay in the transition to the postperovskite phase. Similar to most GdFeO3-type perovskites that transform to the CaIrO3-type postperovskite phase, ZnGeO3 perovskite eventually transformed to the CaIrO3-type postperovskite phase at a critical rotational angle of the GeO6 octahedron. The formation of the postperovskite structure at a very low critical rotational angle for MnGeO3 suggests that relatively large divalent cations likely break down the corner-sharing GeO6 frameworks without a large rotation of GeO6 to form the postperovskite phase.

    Original languageEnglish
    Pages (from-to)11732-11739
    Number of pages8
    JournalInorganic Chemistry
    Volume53
    Issue number21
    DOIs
    Publication statusPublished - Nov 3 2014

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Inorganic Chemistry

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