Lattice Model Results for Pattern Formation in a Mixture with Competing Interactions

Molecules. 2024 Mar 28;29(7):1512. doi: 10.3390/molecules29071512.

Abstract

A monolayer consisting of two types of particles, with energetically favored alternating stripes of the two components, is studied by Monte Carlo simulations and within a mesoscopic theory. We consider a triangular lattice model and assume short-range attraction and long-range repulsion between particles of the same kind, as well as short-range repulsion and long-range attraction for the cross-interaction. The structural evolution of the model upon increasing temperature is studied for equal chemical potentials of the two species. We determine the structure factor, the chemical potential-density isotherms, the specific heat, and the compressibility, and show how these thermodynamic functions are associated with the spontaneous formation of stripes with varying degrees of order.

Keywords: Monte Carlo simulations; colloidal self-assembly; inhomogeneous mixtures; self-assembled stripes; spontaneous pattern formation; theory for mixtures with competing interactions.