Quasi-binary amorphous phase in a 3D system of particles with repulsive-shoulder interactions

TL;DR

This study uses computer simulations to explore the phase diagram of particles with repulsive-shoulder interactions, revealing multiple crystal phases and a glass transition, with the amorphous phase explained via a pseudo-binary mixture model.

Contribution

It provides the first detailed equilibrium phase diagram for a 3D system with repulsive-shoulder interactions, highlighting the emergence of a quasi-binary amorphous phase.

Findings

Identification of multiple crystal phases at low temperatures

Observation of a glass transition in a thermodynamically stable regime

Explanation of amorphous phase as a pseudo-binary mixture

Abstract

We report a computer-simulation study of the equilibrium phase diagram of a three-dimensional system of particles with a repulsive step potential. Using free-energy calculations, we have determined the equilibrium phase diagram of this system. At low temperatures, we observe a number of distinct crystal phases. However, under certain conditions the system undergoes a glass transition in a regime where the liquid appears thermodynamically stable. We argue that the appearance of this amorphous low-temperature phase can be understood by viewing this one-component system as a pseudo-binary mixture.