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Size mismatch effects in oxide solid solutions using Monte Carlo and configurational averaging.
Phys Chem Chem Phys 2005; 7(6):1127-35PC

Abstract

Local minima configurational averaging (CA) and Monte Carlo (MC) simulations are used to examine in detail the variation of thermodynamic and structural properties of binary oxide solid solutions with the volume mismatch between the end members. The maximum volume mismatch studied corresponds to that in the CaO MgO solid solution, a prototype example of a strongly non-ideal system with large miscibility gap. In addition, solid solutions of CaO-HypO using designed hypothetical atoms (Hyp) with atomic radii between those of Ca2+ and Mg2+ have been considered. Calculations on the hypothetical systems allow not only the systematic investigation of size mismatch, but also the detailed examination and comparison of the CA and MC methods. A particularly efficient implementation of the CA method is via the rapid calculation of the radial distribution function (RDF) for all possible arrangements obtained by distributing the different ions on their respective crystallographic sites followed by full structural optimisation of just one configuration from each group with the same RDF. Comparison of results from CA, using optimisations in the static limit, and MC indicates the importance of cell-size and vibrational effects, which can be particularly important for the largest size mismatches. The enthalpies, excess configurational entropies, vibrational entropies and volumes of mixing scale roughly quadratically for all but the largest volume mismatches. Equally sized atoms cluster together in the first coordination shell for all volume mismatches studied.

Authors+Show Affiliations

Department of Chemistry, University of Oslo, Postbox 1033 Blindern, N0315 Oslo, Norway.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19791323

Citation

Mohn, Chris E., et al. "Size Mismatch Effects in Oxide Solid Solutions Using Monte Carlo and Configurational Averaging." Physical Chemistry Chemical Physics : PCCP, vol. 7, no. 6, 2005, pp. 1127-35.
Mohn CE, Lavrentiev MY, Allan NL, et al. Size mismatch effects in oxide solid solutions using Monte Carlo and configurational averaging. Phys Chem Chem Phys. 2005;7(6):1127-35.
Mohn, C. E., Lavrentiev, M. Y., Allan, N. L., Bakken, E., & Stølen, S. (2005). Size mismatch effects in oxide solid solutions using Monte Carlo and configurational averaging. Physical Chemistry Chemical Physics : PCCP, 7(6), pp. 1127-35.
Mohn CE, et al. Size Mismatch Effects in Oxide Solid Solutions Using Monte Carlo and Configurational Averaging. Phys Chem Chem Phys. 2005 Mar 21;7(6):1127-35. PubMed PMID: 19791323.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Size mismatch effects in oxide solid solutions using Monte Carlo and configurational averaging. AU - Mohn,Chris E, AU - Lavrentiev,Mikhail Yu, AU - Allan,Neil L, AU - Bakken,Egil, AU - Stølen,Svein, PY - 2009/10/2/entrez PY - 2005/3/21/pubmed PY - 2005/3/21/medline SP - 1127 EP - 35 JF - Physical chemistry chemical physics : PCCP JO - Phys Chem Chem Phys VL - 7 IS - 6 N2 - Local minima configurational averaging (CA) and Monte Carlo (MC) simulations are used to examine in detail the variation of thermodynamic and structural properties of binary oxide solid solutions with the volume mismatch between the end members. The maximum volume mismatch studied corresponds to that in the CaO MgO solid solution, a prototype example of a strongly non-ideal system with large miscibility gap. In addition, solid solutions of CaO-HypO using designed hypothetical atoms (Hyp) with atomic radii between those of Ca2+ and Mg2+ have been considered. Calculations on the hypothetical systems allow not only the systematic investigation of size mismatch, but also the detailed examination and comparison of the CA and MC methods. A particularly efficient implementation of the CA method is via the rapid calculation of the radial distribution function (RDF) for all possible arrangements obtained by distributing the different ions on their respective crystallographic sites followed by full structural optimisation of just one configuration from each group with the same RDF. Comparison of results from CA, using optimisations in the static limit, and MC indicates the importance of cell-size and vibrational effects, which can be particularly important for the largest size mismatches. The enthalpies, excess configurational entropies, vibrational entropies and volumes of mixing scale roughly quadratically for all but the largest volume mismatches. Equally sized atoms cluster together in the first coordination shell for all volume mismatches studied. SN - 1463-9076 UR - https://www.unboundmedicine.com/medline/citation/19791323/Size_mismatch_effects_in_oxide_solid_solutions_using_Monte_Carlo_and_configurational_averaging DB - PRIME DP - Unbound Medicine ER -