Synthesis of calcium orthocarbonate, Ca2CO4-Pnma at P-T conditions of Earth’s transition zone and lower mantle
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2021-03-05 |
| Journal | American Mineralogist |
| Authors | Jannes Binck, Dominique Laniel, Lkhamsuren Bayarjargal, Saiana Khandarkhaeva, Timofey Fedotenko |
| Institutions | Dassault Systèmes (United Kingdom), Goethe University Frankfurt |
| Citations | 35 |
Abstract
Section titled “Abstract”Abstract We show, by single-crystal diffraction studies in laser-heated diamond-anvil cells, that Ca2CO4 orthocarbonate, which contains CO44− tetrahedra, can be formed already at ~20 GPa at ~1830 K, i.e., at much lower pressures than other carbonates with sp3-hybridized carbon. Ca2CO4 can also be formed at ~89 GPa and ~2500 K. This very broad P-T range suggests the possible existence of Ca2CO4 in the Earth’s transition zone and in most of the lower mantle. Raman spectroscopy shows the typical bands associated with tetrahedral CO44−-groups. DFT-theory based calculations reproduce the experimental Raman spectra and indicate that at least in the athermal limit the phase assemblage of Ca2CO4 + 2SiO2 is more stable than 2CaSiO3 + CO2 at high pressures.
Tech Support
Section titled “Tech Support”Original Source
Section titled “Original Source”References
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