ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The method recently developed to calculate the configurational density of states (or combinatory factor) on the regular solutions alloy model, from Monte Carlo simulation is applied to binary systems having bcc and fcc structures. This method enables one to calculate all the thermodynamic quantities of mixing of the model, including entropy. The results clearly show that the quasichemical approximation, although correct at high temperatures, does not yield a correct temperature dependence of the thermodynamic properties. In bcc alloys with ordering tendency, the Monte Carlo calculations yield configurational entropy curves that, up to now, have been interpreted in terms of the "associated model.'' We show that an exact statistical treatment of the regular solutions model is sufficient to reproduce the strong local order observed at low temperatures. The densities of states themselves are studied; They are Gaussian near the center of the distribution, satisfying the central limit theorem. In the tails of the distribution, the density of states decreases less rapidly with E ; in a certain region of energies, the density of states is roughly exponential, giving rise to a phase transition behavior. At the far extreme of the tails, the density of states decreases faster with energy.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.454818
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