Research output: Contribution to journal › Article › peer-review
Novel Calcium sp3Carbonate CaC2O5- I4¯ 2 d May Be a Carbon Host in Earth's Lower Mantle. / König, Jannes; Spahr, Dominik; Bayarjargal, Lkhamsuren et al.
In: ACS Earth and Space Chemistry, Vol. 6, No. 1, 20.01.2022, p. 73-80.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Novel Calcium sp3Carbonate CaC2O5- I4¯ 2 d May Be a Carbon Host in Earth's Lower Mantle
AU - König, Jannes
AU - Spahr, Dominik
AU - Bayarjargal, Lkhamsuren
AU - Gavryushkin, Pavel N.
AU - Sagatova, Dinara
AU - Sagatov, Nursultan
AU - Milman, Victor
AU - Liermann, Hanns Peter
AU - Winkler, Björn
N1 - Funding Information: The authors acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG)-Germany (FOR2125/CarboPaT, BA4020, WI1232). B.W. is grateful for support by the BIOVIA Science Ambassador program. P.N.G., D.S., and N.S. were supported by the Russian Science Foundation (Project No. 22-23-00925). DESY (Hamburg, Germany), a member of the Helmholtz Association (HGF), is acknowledged for the provision of experimental facilities. Parts of this research were carried out at PETRA III. Publisher Copyright: © 2022 American Chemical Society.
PY - 2022/1/20
Y1 - 2022/1/20
N2 - CaC2O5-I4¯ 2d was obtained by reacting CO2 and CaCO3 at lower Earth mantle pressures and temperatures ranging between 34 and 45 GPa and between 2000 and 3000 K, respectively. The crystal structure was solved by single-crystal X-ray diffraction and contains carbon atoms tetrahedrally coordinated by oxygen. The tetrahedral CO44- groups form pyramidal [C4O10]4- complex anions by corner sharing. Raman spectroscopy allows an unambiguous identification of this compound, and the experimentally determined spectra are in excellent agreement with Raman spectra obtained from density functional theory calculations. CaC2O5-I4¯ 2d persists on pressure release down to ∼18 GPa at ambient temperature, where it decomposes into calcite and, presumably, CO2 under ambient conditions. As polymorphs of CaCO3 and CO2 are believed to be present in the vicinity of subducting slabs within Earth's lower mantle, they would react to give CaC2O5-I4¯ 2d, which therefore needs to be considered instead of end-member CaCO3 in models of the mantle mineralogy.
AB - CaC2O5-I4¯ 2d was obtained by reacting CO2 and CaCO3 at lower Earth mantle pressures and temperatures ranging between 34 and 45 GPa and between 2000 and 3000 K, respectively. The crystal structure was solved by single-crystal X-ray diffraction and contains carbon atoms tetrahedrally coordinated by oxygen. The tetrahedral CO44- groups form pyramidal [C4O10]4- complex anions by corner sharing. Raman spectroscopy allows an unambiguous identification of this compound, and the experimentally determined spectra are in excellent agreement with Raman spectra obtained from density functional theory calculations. CaC2O5-I4¯ 2d persists on pressure release down to ∼18 GPa at ambient temperature, where it decomposes into calcite and, presumably, CO2 under ambient conditions. As polymorphs of CaCO3 and CO2 are believed to be present in the vicinity of subducting slabs within Earth's lower mantle, they would react to give CaC2O5-I4¯ 2d, which therefore needs to be considered instead of end-member CaCO3 in models of the mantle mineralogy.
KW - CaCO
KW - density functional theory
KW - Raman spectroscopy
KW - spcarbonates
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=85122747807&partnerID=8YFLogxK
U2 - 10.1021/acsearthspacechem.1c00284
DO - 10.1021/acsearthspacechem.1c00284
M3 - Article
AN - SCOPUS:85122747807
VL - 6
SP - 73
EP - 80
JO - ACS Earth and Space Chemistry
JF - ACS Earth and Space Chemistry
SN - 2472-3452
IS - 1
ER -
ID: 35242787