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The Connection Between Local Icosahedral Order in Metallic Liquids and the Nucleation of Ordered PhasesOver fifty years ago, David Turnbull showed that the temperature of many metallic liquids could be decreased far below their equilibrium melting temperature before crystallization occurred. To explain those surprising results, Charles Frank hypothesized that the local structures of undercooled metallic liquids are different from those of crystal phases, containing a significant degree of icosahedral order that is incompatible with extended periodicity. Such structural differences must create a barrier to the formation crystal phases, explaining the observed undercooling behavior. If true, the nucleation from the liquid of phases with extended icosahedral order should be easier. Icosahedral order is often favored in small clusters, as observed recently in liquid-like clusters of pure Pb on the (111) surface of Si, for example. However, it has never been shown that an increasing preference for icosahedral phase formation can be directly linked with the development of icosahedral order in the undercooled liquid. Owing to the combination of very recent advances in levitation techniques and the availability of synchrotron x-ray and high flux neutron facilities, this is shown here.
Document ID
20030055152
Acquisition Source
Marshall Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Curreri, Peter A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Kelton, K. F.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Gangopadhyay, A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Lee, G. W.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Hyers, R. W.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Rathz, R. J.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Rogers, J.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Schenk, T.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Simonet, V.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Holland-Moritz, D.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Solid-State Physics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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