TY - JOUR

T1 - High-pressure behavior and stability of synthetic buetschliite K2Ca(CO3)2 up to 19 GPa and 300°C

AU - Likhacheva, Anna Yu

AU - Miloš, Sofija

AU - Romanenko, Alexandr V.

AU - Goryainov, Sergey V.

AU - Semerikova, Anna I.

AU - Rashchenko, Sergey V.

AU - Miletich, Ronald

AU - Shatsky, Anton

N1 - This work is financially supported by the joint RFBR-FWF grant project (# 21-55-14001 and I 5046-N) and performed on state assignment of IGM SB RAS. The XRD characterization was done using the equipment of Research and Education Centre \u201CMolecular Design and Ecologically Safe Technologies\u201D at Novosibirsk State University.

PY - 2024/4

Y1 - 2024/4

N2 - The occurrence of buetschliite, K2Ca(CO3)2, as inclusions in mantle minerals, is considered as one of the keys to understanding phase relationships of dense carbonates and outlines the potential role of potassium carbonates in the Earth's deep carbon cycle. Within this scope, the high-pressure behavior of synthetic buetschliite is characterized by in situ Raman spectroscopy up to 19 GPa and 300°C. Up to 6 GPa, the compression is regular, then the splitting of some of the lattice and internal modes defines the transition to a low-symmetry phase, in analogy to that observed previously in K2Mg(CO3)2. The temperature rise to 300°C shifts the transition pressure from ~6 to ~8 GPa, but on the whole, it does not change the high-pressure behavior of K2Ca(CO3)2. The observed pressure-induced spectral changes are fully reversible at room and elevated temperature. The findings show the expansion of buetschliite baric stability with temperature, which confirms its importance as a constituent of carbonate inclusions in deep minerals.

AB - The occurrence of buetschliite, K2Ca(CO3)2, as inclusions in mantle minerals, is considered as one of the keys to understanding phase relationships of dense carbonates and outlines the potential role of potassium carbonates in the Earth's deep carbon cycle. Within this scope, the high-pressure behavior of synthetic buetschliite is characterized by in situ Raman spectroscopy up to 19 GPa and 300°C. Up to 6 GPa, the compression is regular, then the splitting of some of the lattice and internal modes defines the transition to a low-symmetry phase, in analogy to that observed previously in K2Mg(CO3)2. The temperature rise to 300°C shifts the transition pressure from ~6 to ~8 GPa, but on the whole, it does not change the high-pressure behavior of K2Ca(CO3)2. The observed pressure-induced spectral changes are fully reversible at room and elevated temperature. The findings show the expansion of buetschliite baric stability with temperature, which confirms its importance as a constituent of carbonate inclusions in deep minerals.

KW - buetschliite

KW - high pressure

KW - high temperature

KW - phase transition

KW - potassium carbonate

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85181944487&origin=inward&txGid=4a60e76b2ccd0a2e5c7f1a12be3fdc84

UR - https://www.mendeley.com/catalogue/75e4eae0-1937-3774-afa3-dfda610b6e9d/

U2 - 10.1002/jrs.6654

DO - 10.1002/jrs.6654

M3 - Article

VL - 55

SP - 517

EP - 524

JO - Journal of Raman Spectroscopy

JF - Journal of Raman Spectroscopy

SN - 0377-0486

IS - 4

ER -