Dispersity-Driven Melting Transition in Two Dimensional Solids

TL;DR

This study uses large-scale simulations to explore how particle size dispersity influences the melting behavior of two-dimensional Lennard-Jones solids, revealing a complex phase diagram with novel transitions.

Contribution

It introduces a new phase diagram for 2D solids showing dispersity-driven melting and identifies a potential multicritical point in the dispersity-density space.

Findings

Discovered a threshold dispersity causing melting at high density.

Observed an intermediate hexatic phase at lower densities.

Supported the existence of a multicritical point.

Abstract

We perform extensive simulations of $10^4$ Lennard-Jones particles to study the effect of particle size dispersity on the thermodynamic stability of two-dimensional solids. We find a novel phase diagram in the dispersity-density parameter space. We observe that for large values of the density there is a threshold value of the size dispersity above which the solid melts to a liquid along a line of first order phase transitions. For smaller values of density, our results are consistent with the presence of an intermediate hexatic phase. Further, these findings support the possibility of a multicritical point in the dispersity-density parameter space.