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 language | English |
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Pages (from-to) | 52-59 |
Number of pages | 8 |
Journal | Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2005 |
Keywords
- Coordination change
- Germanate
- Local structure
- Melt
- Synchrotron radiation
- XAFS
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics