Phase separation in a binary mixture of sticky spheres

Abstract

We report an extensive and systematic investigation of the dependence of range of attractive potential on the phase separation of 2D binary systems. Langevin dynamics simulations are carried out for different ranges of attraction while keeping the depth of the potential well constant. We examine the phase behavior of the binary mixture while the system is cooled from a high temperature to low temperatures. When the range of attractive interactions approaches the sticky sphere limit, the system undergoes a phase separation at lower temperatures. When quenched rapidly, the system mixes again upon further reduction in the temperature and enters into glassy state. This reentrant mixing is not observed when the system is quenched slowly. In contrast, such a phase separation is not observed in systems with a larger interaction range. In the fast quenching, one of the components of the mixture chooses to be in crystalline configuration while the other being in disordered state when demixing happens. In the slow quenching, both components prefer to be in crystalline configuration when phase separated.