Phonon modes and vibrational entropy of mixing in Fe-Cr
- California Institute of Technology, mail 138-78, Pasadena, California 91125 (United States)
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)
Results from neutron inelastic-scattering experiments on Fe, Cr, and three bcc Fe-Cr alloys were analyzed with a Born--von Karman model to obtain phonon density-of-states (DOS) curves. We compared the phonon DOS of the bcc Fe-Cr alloys to the composite phonon DOS from appropriate fractions of the phonon DOS of the pure metals Fe and Cr. In the high-temperature limit, we obtained the vibrational entropy of mixing of Fe and Cr to be 0.141, 0.201, and 0.214 {ital k}{sub {ital B}}/atom for alloys of Fe{sub 70}Cr{sub 30},Fe{sub 53}Cr{sub 47}, and Fe{sub 30}Cr{sub 70}, respectively, with the disordered solid solution having the larger vibrational entropy. Some expected effects of vibrational entropy on the chemical unmixing transformation in Fe-Cr are discussed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-84OR21400; FG03-86ER45270
- OSTI ID:
- 83930
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 52, Issue 5; Other Information: PBD: 1 Aug 1995
- Country of Publication:
- United States
- Language:
- English
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