Synthesis of calcium orthocarbonate, Ca2CO4-Pnma at P-T conditions of Earth's transition zone and lower mantle

Title data

Binck, Jannes ; Laniel, Dominique ; Bayarjargal, Lkhamsuren ; Khandarkhaeva, Saiana ; Fedotenko, Timofey ; Aslandukov, Andrii ; Glazyrin, Konstantin ; Milman, Victor ; Chariton, Stella ; Prakapenka, Vitali B. ; Dubrovinskaia, Natalia ; Dubrovinsky, Leonid ; Winkler, Björn:
Synthesis of calcium orthocarbonate, Ca2CO4-Pnma at P-T conditions of Earth's transition zone and lower mantle.
In: American Mineralogist. Vol. 107 (2022) Issue 3 . - pp. 336-342.
ISSN 1945-3027
DOI: https://doi.org/10.2138/am-2021-7872

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Abstract in another language

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.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Professor Materials Physics and Technology at Extreme Conditions Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Professor Materials Physics and Technology at Extreme Conditions > Professor Materials Physics and Technology at Extreme Conditions - Univ.-Prof. Dr. Natalia Doubrovinckaia Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	29 Apr 2022 06:59
Last Modified:	29 Apr 2022 07:00
URI:	https://eref.uni-bayreuth.de/id/eprint/69470