Theoretical description of cluster formation in two- Yukawa competing fluids

We investigate the temperature threshold whereupon two-Yukawa systems with microscopic competing interactions transform from normal fluids to "cluster fluids". Specifically, we apply two refined, thermodynamically self-consistent integral equation theories of the liquid state to study a family of two-Yukawa models having the same interaction strength, independent of the choice of potential parameters. We find, over the range of potential parameters and fluid densities investigated, an almost linear scaling between the temperature threshold for the cluster formation and the height of repulsive interactions, with higher barriers stabilizing the cluster fluid at higher temperatures. Cluster–cluster correlation lengths seem instead to be influenced by the long-range features of the interactions.