UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Thermochemistry of strontium incorporation in aragonite from atomistic simulations
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Article
  • Authors:
    Ruiz-Hernandez SE, Grau-Crespo R, Ruiz-Salvador AR, De Leeuw NH
  • Publisher:
    PERGAMON-ELSEVIER SCIENCE LTD
  • Publication date:
    15/02/2010
  • Pagination:
    1320, 1328
  • Journal:
    GEOCHIM COSMOCHIM AC
  • Volume:
    74
  • Issue:
    4
  • Print ISSN:
    0016-7037
  • Language:
    EN
  • Keywords:
    MOLECULAR-DYNAMICS SIMULATIONS, FREE-ENERGY MINIMIZATION, SOLID-SOLUTIONS, SR COORDINATION, CORAL ARAGONITE, THERMODYNAMIC PROPERTIES, CALCITE, GROWTH, TEMPERATURE, CACO3
  • Addresses:
    Grau-Crespo, R
    UCL
    Dept Chem
    London
    WC1H 0AJ
    England

    Natl Aquarium Cuba
    Havana
    Cuba
Abstract
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 similar to 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. (C) 2009 Elsevier Ltd. All rights reserved.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by