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Study of high-pressure thermophysical properties of orthocarbonate Sr 3 CO 5 using deep learning molecular dynamics simulations.
- Source :
-
Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2024 Feb 14; Vol. 26 (7), pp. 6351-6361. Date of Electronic Publication: 2024 Feb 14. - Publication Year :
- 2024
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Abstract
- The exploration of the physical attributes of the recently discovered orthocarbonate Sr <subscript>3</subscript> CO <subscript>5</subscript> is significant for comprehending the carbon cycle and storage mechanisms within the Earth's interior. In this study, first-principles calculations are initially used to examine the structural phase transitions of Sr <subscript>3</subscript> CO <subscript>5</subscript> polymorphs within the range of lower mantle pressures. The results suggest that Sr <subscript>3</subscript> CO <subscript>5</subscript> with the Cmcm phase exhibits a minimal enthalpy between 8.3 and 30.3 GPa. As the pressure exceeds 30.3 GPa, the Cmcm phase undergoes a transition to the I 4/ mcm phase, while the experimentally observed Pnma phase remains metastable under our studied pressure. Furthermore, the structural data of SrO, SrCO <subscript>3</subscript> , and Sr <subscript>3</subscript> CO <subscript>5</subscript> polymorphs are utilized to develop a deep learning potential model suitable for the Sr-C-O system, and the pressure-volume relationship and elastic constants calculated using the potential model are in line with the available results. Subsequently, the elastic properties of Cmcm and I 4/ mcm phases in Sr <subscript>3</subscript> CO <subscript>5</subscript> at high temperature and pressure are calculated using the molecular dynamics method. The results indicate that the I 4/ mcm phase exhibits higher temperature sensitivity in terms of elastic moduli and wave velocities compared to the Cmcm phase. Finally, the thermodynamic properties of the Cmcm and I 4/ mcm phases are predicted in the range of 0-2000 K and 10-120 GPa, revealing that the heat capacity and bulk thermal expansion coefficient of both phases increase with temperature, with the constant volume heat capacity gradually approaching the Dulong-Petit limit as the temperature rises.
Details
- Language :
- English
- ISSN :
- 1463-9084
- Volume :
- 26
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Physical chemistry chemical physics : PCCP
- Publication Type :
- Academic Journal
- Accession number :
- 38315085
- Full Text :
- https://doi.org/10.1039/d3cp04833k