Journal
JOURNAL OF ALLOYS AND COMPOUNDS
Volume 708, Issue -, Pages 1063-1072Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jallcom.2017.03.018
Keywords
DFT; Thermodynamic model; Nickel; Oxygen; Clusters
Categories
Funding
- CALMIP [2016-p0912, 2014-p0912, 2015-p0912]
Ask authors/readers for more resources
Combining thermodynamic concepts with first-principles calculations, we study the solubility of oxygen atoms (O) in nickel. In our approach, we include the possible formation of oxygen clusters (On) and vacancies-oxygens clusters (VOn and V2On). We show that the vacancy-oxygens interactions are strong (approximately 1 eV) and would induce a large concentration of clusters in fcc-Ni. The use of a thermodynamic model, within a grand canonical approach, allows calculation of the vacancy concentration, including these VOn clusters, as a function of O concentration, for different temperatures. We find that at low temperatures (below 600 K), a small content of oxygen (in appm) strongly modifies the vacancy concentration, increasing the total vacancy concentration in the metal by many orders of magnitude more than the thermal vacancy concentration. The vacancy concentration is thus directly controlled by the oxygen content in the metal. At high temperatures, the effect is reduced, becoming negligible near the melting point. These results show the strong impact of interstitial atoms on the vacancy concentration. The influence of the vacancy formation energy is also discussed. (C) 2017 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available