Island formation without attractive interactions

TL;DR

This paper demonstrates that surface adsorbates can form islands driven by entropy from repulsive interactions, not attraction, potentially explaining observed island formation in certain systems.

Contribution

It introduces a novel mechanism where entropy from repulsive interactions causes island formation, challenging the traditional attraction-based understanding.

Findings

Adsorbates can form islands without attractive forces.

Repulsive interactions can increase entropy, leading to island formation.

This mechanism may explain experimental observations in O/Pt(111).

Abstract

We show that adsorbates on surfaces can form islands even if there are no attractive interactions. Instead strong repulsion between adsorbates at short distances can lead to islands, because such islands increase the entropy of the adsorbates that are not part of the islands. We suggest that this mechanism cause the observed island formation in O/Pt(111), but it may be important for many other systems as well.