Phase stability of Ni–Al nanoparticles
The phase stability of Ni–Al clusters of nanometer size was studied by using the embedded atom model and Monte Carlo simulation techniques. For temperatures of 500 and 1000 K and for a range of compositions below 70 at.% Al, the equilibrium structures of the system were determined and compared with...
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Published in | Journal of materials research Vol. 14; no. 7; pp. 2849 - 2854 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
New York, USA
Cambridge University Press
01.07.1999
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Online Access | Get full text |
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Summary: | The phase stability of Ni–Al clusters of nanometer size was studied by using the embedded atom model and Monte Carlo simulation techniques. For temperatures of 500 and 1000 K and for a range of compositions below 70 at.% Al, the equilibrium structures of the system were determined and compared with the bulk results. We found that the bulk NiAl (B2) and Ni3Al (L12) phases were stable phases in the nanoparticle system; however, for deviations from ideal composition, the analysis revealed that, because of the surface effect, the composition of the clusters was not uniform. There was a core region in which the structure was ordered, B2 or L12, with a composition very close to the ideal, and a chemically disordered mantle region that allocated the deviations from ideal stoichiometries; in this way, a larger phase field appeared, indicating trends similar to those found in experiments on nanocrystalline Ni–Al powder [S.K. Pabi and B.S. Murty, Mater. Sci. Eng. A214, 146 (1996)]. For concentrations between 37 and 51 at.% Al, an intermediate phase, similar to the tetragonal L10 martensite, appeared. |
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Bibliography: | PII:S0884291400050834 istex:2399BF69F6A57864AA772DF888F4B8AECEE4A7F3 ark:/67375/6GQ-P8NTJ1HC-4 ArticleID:05083 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0884-2914 2044-5326 |
DOI: | 10.1557/JMR.1999.0380 |