Phase separation in a binary mixture of sticky spheres

TL;DR

This study uses simulations to explore how the range of attractive forces affects phase separation in 2D binary mixtures, revealing a reentrant mixing behavior near the sticky sphere limit.

Contribution

It demonstrates that decreasing the interaction range induces first-order phase separation and reentrant mixing, highlighting the role of attraction range in binary mixture phase behavior.

Findings

Phase separation occurs at lower temperatures as the attraction range approaches the sticky sphere limit.

Further cooling causes the system to re-mix, indicating reentrant behavior.

In phase-separated states, one component forms a crystalline structure while the other remains disordered.

Abstract

We numerically investigate the dependence of range of attractive potential on the phase separation of 2-D binary systems. Through extensive simulations and analysis, we show that when the range of attractive interactions approaches the sticky sphere limit, the system undergoes a phase separation at lower temperature. Further reduction in temperature causes the system to mix again. These mixing-demixing-mixing transitions are of first order. Such phase separation is not observed for systems with larger interaction range. In the phase separated region of the phase diagram, one of the components of the mixture chooses to be in crystalline configuration, while other being in disordered state