Publication Date:
2021-05-19
Description:
We have investigated the thermodynamics of mixing between aragonite (orthorhombic CaCO3) and strontianite (SrCO3).
In agreement with experiment, our simulations predict that there is a miscibility gap between the two solids at ambient conditions.
All SrxCa1 xCO3 solids with compositions 0.12 〈 x 〈 0.87 are metastable with respect to separation into a Ca-rich
and a Sr-rich phase. The concentration of Sr in coral aragonites (x 0.01) lies in the miscibility region of the phase diagram,
and therefore formation of separated Sr-rich phases in coral aragonites is not thermodynamically favorable. The miscibility
gap disappears at around 380 K. The enthalpy of mixing, which is positive and nearly symmetric with respect to x = 0.5, is the
dominant contribution to the excess free energy, while the vibrational and configurational entropic contributions are small
and of opposite sign. We provide a detailed comparison of our simulation results with available experimental data.
Se investigó la actividad termodinámica existente entre la mezcla de la aragonita y el estroncio. Se ofrecen todos los datos experimentales y los resultados de la simulación efectuada predicen que hay un vacío en condiciones de ambiente.
Description:
Published
Description:
aragonita, estroncio, arrecife de coral, actividad termodinámica
Keywords:
Strontium
;
Aragonite
;
Coral reefs
;
Thermodynamic activity
;
Strontium
Repository Name:
AquaDocs
Type:
Journal Contribution
,
Non-Refereed
,
Article
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