Data/hora: 11/06/2024 06:44:08

Provedor de dados: 	20	
País: 	Belgium	
Título: 	Thermochemistry of strontium incorporation in aragonite from atomistic simulations	
Autores: 	Grau-Crespo, R.; Ruiz-Hernández, S. E.; Ruiz-Salvador, A. R.; De Leeuw, N. H.	
Data: 	2011-08-12	
Ano: 	2010	
Palavras-chave: 	1246; Aragonite; Coral reefs; Thermodynamic activity; Strontium; Strontium.	
Resumo: 	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 &lt; x &lt; 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.	
Tipo: 	Journal Contribution	
Idioma: 	Inglês	
Identificador: 	Geochimica et Cosmochimica Acta, 74(2010). p. 1320-1328

0016-7037

http://hdl.handle.net/1834/4103	
Editor: 	Elsevier	
Relação: 	doi:10.1016/j.gca.2009.10.049