Eutectic point in a simple lattice gas model

TL;DR

This paper uses Monte Carlo simulations of a simple lattice gas model to analyze the phase diagram of sulphur adsorbed on ruthenium(0001), identifying critical points and phase coexistence regions consistent with experimental observations.

Contribution

It introduces a simple lattice gas model with repulsive interactions to accurately reproduce the phase diagram of S/Ru(0001), including tricritical and eutectic points.

Findings

Identification of two tricritical points

Discovery of three coexistence regions

Confirmation of a eutectic point in the phase diagram

Abstract

We investigate the phase diagram and the critical properties of the adsorbate system sulphur/ruthenium(0001) in the coverage region $\frac{1}{4} < \Theta < \frac{1}{3}$ by means of Monte-Carlo simulations of a simple lattice gas model on a triangular lattice. The model contains only repulsive nearest and next-nearest neighbor interactions. Combining results obtained by using both Glauber and Kawasaki kinetics in the simulations we identify two tricritical points, three coexistence regions and a eutectic point in the phase diagram of the system. Our results agree with the findings of recent experimental work on S/Ru(0001). Furthermore we are able to add certain details to the experimentally observed phase diagram.