Analytical Electron Microscopy of Garnet-Perovskite Phase Transformation.

• Miyajima Nobuyoshi

  Graduate school of Science, Hokkaido University

• Fujino Kiyoshi

  Graduate school of Science, Hokkaido University

• Funamori Nobumasa

  Institute for Solid State Physics, University of Tokyo Now at Department of Geology and Geophysics, University of California

• Kondo Tadashi

  Institute for Solid State Physics, University of Tokyo

• Yagi Takehiko

  Institute for Solid State Physics, University of Tokyo

Bibliographic Information

Other Title

• 分析電顕によるガーネット‐ペロブスカイト相変態の研究
• ブンセキ デンケン ニヨル ガーネット ペロブスカイトソウ ヘンタイ ノ ケン

Abstract

Natural pyrope garnets have been transformed at 35-60 GPa by a laser-heated diamond anvil cell (DAC), and the recovered samples were examined with an analytical electron microsoope (AEM). Orthorhombic perovskite was the dominant product phase after the transformation, and the Al content in perovskite increases with pressure and temperature. However, Al-rich perovskite was metastably inverted into the lithium niobate phase during the decompression. The mode of transition behavior of orthorhombic perovskite to the lithium niobate phase varies with the Al content in orthorhombic perovskite. Orthorhombic perovskite with less than 25 mol % Al₂O₃ can be quenched as orthorhombic perovskite after the release of pressure. In contrast, perovskite with about 25-28 mol% Al₂O₃ becomes the alternating lamellae of orthorhombic perovskite and the lithium niobate phases, having the topotactic relation with each other after the decompression. With further increasing the Al₂O₃ content in perovskite, it is completely converted into the lithium niobate phase with polysynthetic twinning on {1012}_hex. From this study, it was proved that, even for Al-rich garnets, the dominant post-garnet phase under the lower mantle condition is orthorhombic perovskite.

Journal

• The Review of High Pressure Science and Technology

  The Review of High Pressure Science and Technology 6 (4), 230-235, 1997

  The Japan Society of High Pressure Science and Technology

Keywords

• DAC
• AEM
• garnet-perovskite transformation
• orthorhombic perovskite-lithium niobate phase transition
• topotactic relation polysynthetic twinning

Details

• CRID: 1390001204382363264
• NII Article ID: 10002848857
• NII Article ID: 10004196034
• NII Book ID: AN10452913
• DOI: 10.4131/jshpreview.6.230
• COI: 1:CAS:528:DyaK1cXmslGltg%3D%3D
• ISSN: 13481940
• ISSN: 0917639X
• ISSN: http://id.crossref.org/issn/0917639X
• NDL BIB ID: 4367807
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4367807
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed