Pressure-induced structural change of liquid germanate

Hiroshi Arima, Osamu Ohtaka, Akira Yoshiasa

Research output: Contribution to journalReview articlepeer-review

Abstract

Local structures around germanium in liquid germanate have been investigated by in-situ X-ray absorption measurements up to 9 GPa at 1000°C. Liquid germanate consisting of tetrahedrally coordinated germanium contracts with increasing pressure without significant changes in the local structure up to 2.5 GPa and then shows an abrupt fourfold-sixfold coordination change around 3 GPa. The coordination change is completed below 4 GPa and a high-density liquid consisting of octahedrally coordinated germanium is stable to 9 GPa. GeO6 octahedron in the high-density liquid is more compressible than that in solids, suggesting the possibility of a density inversion between liquid and solid at higher pressure. By considering the analogy of germanates to silicates, these results give some far-reaching implications for the evolution and dynamics of the Earth's deep interior.

Original languageEnglish
Pages (from-to)52-59
Number of pages8
JournalReview of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu
Volume15
Issue number1
DOIs
Publication statusPublished - 2005

Keywords

  • Coordination change
  • Germanate
  • Local structure
  • Melt
  • Synchrotron radiation
  • XAFS

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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