Issue |
Europhys. Lett.
Volume 62, Number 1, April 2003
|
|
---|---|---|
Page(s) | 42 - 48 | |
Section | Condensed matter: structure, mechanical and thermal properties | |
DOI | https://doi.org/10.1209/epl/i2003-00357-4 | |
Published online | 01 March 2003 |
Dynamic structure in a molten binary alloy by ab initio molecular dynamics: Crossover from hydrodynamics to the microscopic regime
1
Departamento de Física Teórica, Universidad de Valladolid
- 47011 Valladolid, Spain
2
Department of Physics, Queen's University - Kingston,
K7L 3N6 Ontario, Canada
Received:
15
November
2002
Accepted:
23
January
2003
The dynamic structure factor of the
liquid alloy at T=590
has
been calculated by ab initio molecular-dynamics
simulations using 2000 particles. For small wave vectors,
, we find clear side peaks in the
partial dynamic structure factors. Whereas for
the peak frequencies correspond to the
hydrodynamic sound dispersion of the binary alloy, for greater
q-values we obtain two modes with phase velocities above and
below the hydrodynamic sound. A smooth transition between
hydrodynamic sound and the two collective modes is shown to take
place in the range
. The
mass ratio in this system,
, is the smallest one so far for which the fast mode is
observed. We also predict that inelastic X-ray scattering
experiments would be able to detect the slow mode, and explain
why the inelastic neutron scattering measurements
(GARTRELL-MILLS P. R. et al.,
Physica B, 154 (1988) 1)
do not show any of these modes.
PACS: 61.20.Ja – Computer simulation of liquid structure / 61.20.Lc – Time-dependent properties; relaxation / 61.25.Mv – Liquid metals and alloys
© EDP Sciences, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.