Effects of confinement on pattern formation in two dimensional systems with competing interactions.

Area of Science:

• Soft Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Particle monolayers with competing interactions exhibit complex self-assembly.
• Template-assisted confinement influences pattern formation and thermodynamic properties.

Purpose of the Study:

• Investigate template-assisted pattern formation in particle monolayers with SALR interactions.
• Analyze the effect of wall separation and temperature on stripe morphology and stability.
• Characterize the transition from ordered stripes to disordered structures.

Main Methods:

• Monte Carlo simulations of a generic model for particles with SALR interactions.
• Study of monolayers confined between parallel walls with varying separation (L2).
• Analysis of structural morphology and thermodynamic functions across a range of temperatures (T).

Main Results:

• At low T, parallel stripes form, parallel to confining walls, with minor corrugation if L2 is non-optimal.
• Stripe integrity is maintained across various L2, but order is lost above a L2-dependent Kelvin temperature (TK(L2)).
• Above TK(L2), topological defects like stripe breaking/branching appear, yet some orientational anisotropy persists; at high T, an isotropic fluid of clusters forms.

Conclusions:

• The study elucidates the temperature-driven transition from ordered striped patterns to disordered states in confined particle monolayers.
• A Kelvin-like equation describes the temperature dependence of stripe stability, with heat capacity peaking at this transition for optimal L2.
• The findings provide insights into self-assembly phenomena in confined soft matter systems.