Phase diagram of a two-dimensional lattice gas model of a ramp system

摘要

Using Monte Carlo simulation and fundamental measure theory we study the phase diagram of atwo-dimensional lattice gas model with a nearest neighbor hard core exclusion and a next-to-nearestneighbor finite repulsive interaction. The model presents two competing ranges of interaction and,in common with many experimental systems, exhibits a low density solid phase, which melts backto the fluid phase upon compression. The theoretical approach is found to provide a qualitativelycorrect picture of the phase diagram of our model system.