The entropy of alloys.
- Marius
A major problem in simulating thermodynamic properties of alloys is modeling the entropy. While configurational entropy is incorporated in most stability calculations, the other components, such as the vibrational and electronic entropy are often neglected or roughly estimated. In this work we propose a method of accounting for both configurational and vibrational entropy and discuss the electronic contribution for several actinide based alloys. The meaning of entropy in non-equilibrium thermodynamic processes is also discussed and illustrated for the case of phase transformations and diffusion. The influence of temperature on the enthalpy and free energy of delta-Pu-Ga phase, as resulted from Modified Embedded Atom Method (MEAM), and the influence of Ga content on the enthalpy and free energy of delta-Pu-Ga phase are discussed. The analysis of the thermodynamic properties of the fcc Pu-Ga phase, as calculated with MEAM shows that the vibrational entropy contribution to the free energy is ve ry important and non-linear with temperature. The free energy also changes with the Ga content.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 977825
- Report Number(s):
- LA-UR-04-5861; TRN: US201012%%747
- Resource Relation:
- Conference: Submitted to: TOFA 2004 - Discussion Meeting on Thermodynamics of Alloys, Sept.12-17, 2004, Vienna, Austria.
- Country of Publication:
- United States
- Language:
- English
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