Subsolidus phase relations in Ca2Mo2O8?NaEuMo2O8powellite solid solution predicted from static lattice energy calculations and Monte Carlo simulations
Access Status
Authors
Date
2008Collection
Type
Metadata
Show full item recordAbstract
Thermodynamic mixing properties and subsolidus phase relations of Ca2Mo2O8?NaEuMo2O8powellites were modelled in the temperature range of 423?1773 K with static lattice energy calculations based on empirically constrained interatomic potentials. Relaxed static lattice energies (SLE) of a large set of randomly varied structures in a 4 4 2 supercell of I41/a powellite (a = 5.226 A , c = 11.433 A ) containing 128 exchangeable (Ca, Na and Eu) atoms were calculated using the general utility lattice program (GULP). These energies were cluster expanded in the basis set of 69 pairwise effective interactions and three configurationindependent parameters. Temperaturedependent enthalpies of mixing were calculated using the Monte Carlo method. Free energies of mixing were obtained by thermodynamic integration of the Monte Carloresults. The simulations suggest that the NaEuMo2O8 endmember is nearly fully ordered and has I4 symmetry. The calculated subsolidus temperaturecomposition phase diagram is dominated by three miscibility gaps which are separated by narrow fields of stability of two ordered phases with the compositions of x = 4/9 and x = 2/3, where x is the mole fraction of the NaEuMo2O8 endmember.
Citation
Source Title
DOI
Faculty
Department
Related items
Showing items related by title, author, creator and subject.

Taylor, Zoe Rebecca (2011)There has been a recent focus on investigating the properties of semiconductors at the nanoscale as it is well known that the bandgap of semiconducting materials is altered due to quantum confinement effects. The ...

Vinograd, V.; JuarezArellano, E.; Leib, A.; Knorr, K.; Schnick, W.; Gale, Julian; Winkler, B. (2007)The fractions of aluminium, [Al]/[Al+Si], and oxygen, [O]/[O] in crystallographically distinct sites of BaYb[Si4xAlxOxN7x] oxonitridoaluminosilicate (space group P63mc, No. 186) were refined based on the results of ...

Vinograd, V.; Burton, B.; Gale, Julian; Allan, N.; Winkler, B. (2006)Thermodynamic mixing properties and subsolidus phase relations of the rhombohedral carbonate system, (1  x) CaCO3  x MgCO3, were modelled in the temperature range of 6232023 K with static structure energy calculations ...