Solute–solute correlations responsible for the prepeak in structure factors of undercooled Al-rich liquids: A molecular dynamics study
- Ames Lab., Ames, IA (United States)
- Ames Lab., Ames, IA (United States); Univ. of Science and Technology of China, Anhui (People's Republic of China)
- Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
- Univ. of Science and Technology of China, Anhui (People's Republic of China)
In this study, we have performed molecular dynamics simulations on a typical Al-based alloy Al90Sm10. The short-range and medium-range correlations of the system are reliably produced by ab initio calculations, whereas the long-range correlations are obtained with the assistance of a semi-empirical potential well-fitted to ab initio data. Our calculations show that a prepeak in the structure factor of this system emerges well above the melting temperature, and the intensity of the prepeak increases with increasing undercooling of the liquid. These results are in agreement with x-ray diffraction experiments. The interplay between the short-range order of the system originating from the large affinity between Al and Sm atoms, and the intrinsic repulsion between Sm atoms gives rise to a stronger correlation in the second peak than the first peak in the Sm–Sm partial pair correlation function (PPCF), which in turn produces the prepeak in the structure factor.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1227301
- Alternate ID(s):
- OSTI ID: 1238820
- Report Number(s):
- IS-J-8634
- Journal Information:
- Journal of Physics. Condensed Matter, Vol. 27, Issue 20; ISSN 0953-8984
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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