1. Self-diffusion and microscopic dynamics in a gold-silicon liquid investigated with quasielastic neutron scattering
- Author
-
Zach Evenson, Andreas Meyer, Fan Yang, and Giovanna G. Simeoni
- Subjects
Self-diffusion ,Physics and Astronomy (miscellaneous) ,Institut für Materialphysik im Weltraum ,Chemistry ,Neutron diffraction ,02 engineering and technology ,Activation energy ,021001 nanoscience & nanotechnology ,01 natural sciences ,Dynamics ,Condensed Matter::Soft Condensed Matter ,Crystallography ,Gold Atoms ,Chemical physics ,hydrodynamic theory ,0103 physical sciences ,Quasielastic neutron scattering ,Melting point ,Relaxation (physics) ,Exponential decay ,010306 general physics ,0210 nano-technology ,Eutectic system - Abstract
We use incoherent quasielastic neutron scattering to study the atomic dynamics of gold in a eutectic Au81Si19 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.
- Published
- 2016