Phase behaviour of Lennard-Jones particles in two dimensions

Abstract

The phase diagram of the prototypical two-dimensional Lennard-Jones system, while extensively investigated, is still debated. In particular, there are controversial results in the literature as concern the existence of the hexatic phase and the melting scenario. Here, we study the phase behaviour of 2D LJ particles via large-scale numerical simulations. We demonstrate that at high temperature, when the attraction in the potential plays a minor role, melting occurs via a continuous solid-hexatic transition followed by a first-order hexatic-fluid transition. As the temperature decreases, the density range where the hexatic phase occurs shrinks so that at low-temperature melting occurs via a first-order liquid-solid transition. The temperature where the hexatic phase disappears is well above the liquid-gas critical temperature. The evolution of the density of topological defects confirms this scenario.

References in corpus (4)

• 2D Melting: From Liquid-Hexatic Coexistence to Continuous Transitions
• Disappearance of the hexatic phase in a binary mixture of hard disks
• Attraction tames two-dimensional melting: from continuous to discontinuous transitions
• Accurate determination of the translational correlation function of two-dimensional solids

Cited by in corpus (8)

• Time-(ir)reversibility in active matter: from micro to macro
• The role of attraction in the phase diagrams and melting scenarios of generalized 2D Lennard-Jones systems
• The Liquid--Hexatic Transition for Soft Disks
• Melting of the two-dimensional solid phase in the Gaussian-core model
• A Critical Edge Number Revealed for Phase Stabilities of Two-Dimensional Ball-Stick Polygons
• Collective dynamics and shattering of disturbed two-dimensional Lennard-Jones crystals
• Self-assembly of anisotropic particles on curved surfaces
• Atomistic mechanisms of viscosity in 2D liquid-like fluids