Searching for various melting scenarios of 2D crystals

TL;DR

This paper explores the diverse melting behaviors of 2D crystals, highlighting various scenarios including newly observed types, and discusses the limitations of existing theories in predicting all possible melting pathways.

Contribution

It introduces new melting scenarios for 2D crystals and emphasizes the potential for additional pathways beyond current theoretical predictions.

Findings

Five melting scenarios observed, including two new types.

Simulation results show shape tuning affects melting pathways.

Existing theories do not account for all possible melting behaviors.

Abstract

In contrast to three-dimensional (3D) crystals that melt via a first-order transition, two-dimensional (2D) crystals can exhibit various melting scenarios under different temperatures, pressures, and particle interactions, particularly when they can form partially ordered intermediate phases between crystal and liquid. The existing 2D melting theories predict some scenarios, but do not exclude other possibilities. A recent simulation observed five melting scenarios including two new types by tuning the shape of polygonal particles.