Speaker
Ulf Pedersen
(Roskilde University, Denmark)
Description
The binary Kob-Andersen (KA) Lennard-Jones mixture is the
standard model for computational studies of viscous liquids
and the glass transition. For very long runs the viscous KA
system crystallizes, however, by phase separating into a
pure A particle phase forming an FCC crystal. We present the
phase diagram for KA-type mixtures showing, in particular,
that the freezing temperature of the standard KA system at
liquid density 1.2 is 1.028(3). At large B particle
concentrations the system crystallizes into the CsCl crystal
structure. The eutectic corresponding to the FCC and CsCl
structures is cut-off in a narrow interval of B particle
concentrations around 25% at which the PuBr3 structure is
the thermodynamically stable phase. The melting
temperature's variation with B particle concentration at two
other pressures, as well as at the constant density 1.2, are
predicted from the simulations using isomorph theory.
Interface-pinning simulations confirm these predictions. Our
data demonstrate approximate identity between the melting
temperature and the onset temperature below which viscous
dynamics appears.
