Approximations for vibrational thermodynamics of disordered alloys: Effective supercells and the quasiharmonic method
- Univ. of California, Berkeley, CA (United States)
- Sandia National Labs., Livermore, CA (United States). Computational Materials Science Dept.
- Univ. of Illinois, Urbana, IL (United States). Dept. of Materials Science and Engineering
Recent work has suggested that vibrational effects can play a significant role in determining alloy phase equilibria. In order to better understand these effects and the methods used in their calculation, the authors investigate the vibrational properties of disordered Ni{sub 3}Al using the Embedded-Atom Method. They examine the effectiveness of the Special Quasirandom Structure (SQS) approximation, and find that an SQS-8 can accurately represent the vibrational thermodynamics of the disordered state. By the use of Monte Carlo (MC) techniques, they also find that the quasiharmonic approximation becomes less accurate as they approach the melting temperature, but that the accuracy may be extended to higher temperatures by resorting to the MC equation of state giving the specific volume as a function of temperature.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000; AC03-76SF00098; FG02-91ER45439
- OSTI ID:
- 323457
- Report Number(s):
- CONF-971201-; TRN: IM9911%%70
- Resource Relation:
- Conference: 1997 fall meeting of the Materials Research Society, Boston, MA (United States), 1-5 Dec 1997; Other Information: PBD: 1998; Related Information: Is Part Of Phase transformations and systems driven far from equilibrium; Ma, E. [ed.] [Louisiana State Univ., Baton Rouge, LA (United States)]; Atzmon, M. [ed.] [Univ. of Michigan, Ann Arbor, MI (United States)]; Bellon, P. [ed.] [Univ. of Illinois, Urbana, IL (United States)]; Trivedi, R. [ed.] [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States)]; PB: 703 p.; Materials Research Society symposium proceedings, Volume 481
- Country of Publication:
- United States
- Language:
- English
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