Self-diffusion and microscopic dynamics in a gold-silicon liquid investigated with quasielastic neutron scattering

Journal Article · Mon Mar 21 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4944814· OSTI ID:22591465

Evenson, Zach ^[1]; Yang, Fan; Meyer, Andreas ^[2]; Simeoni, Giovanna G. ^[1]

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1. Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department, Technische Universität München, Lichtenbergstrasse 1, 85748 Garching (Germany)
2. Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany)

We use incoherent quasielastic neutron scattering to study the atomic dynamics of gold in a eutectic Au{sub 81}Si{sub 19} melt. Despite the glass-forming nature of this system, the gold self-diffusivity displays an Arrhenius behavior with a low activation energy characteristic of simple liquids. At high temperatures, long-range transport of gold atoms is well described by hydrodynamic theory with a simple exponential decay of the self-correlation function. On cooling towards the melting temperature, structural relaxation crosses over to a highly stretched exponential behavior. This suggests the onset of a heterogeneous dynamics, even in the equilibrium melt, and is indicative of a very fragile liquid.

• OSTI ID: 22591465
• Journal Information: Applied Physics Letters, Vol. 108, Issue 12; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTIVATION ENERGY
ATOMS
COOLING
CORRELATION FUNCTIONS
CORRELATIONS
GOLD
LIQUIDS
MELTING
MELTING POINTS
NEUTRON REACTIONS
QUASI-ELASTIC SCATTERING
SELF-DIFFUSION
SILICON