Anomalous phase behavior in a model fluid with only one type of local structure

TL;DR

This paper demonstrates that anomalous phase behaviors like reentrant melting and polymorphism can occur in a simple fluid model with a single local structure, without requiring multiple particle populations.

Contribution

It shows that weak softening of repulsion alone can induce a wide range of anomalous behaviors, broadening the understanding of phase anomalies in simple systems.

Findings

Reentrant melting observed in the model.

Presence of solid polymorphism.

Thermodynamic, dynamic, and structural anomalies identified.

Abstract

We present evidence that the concurrent existence of two populations of particles with different effective diameters is not a prerequisite for the occurrence of anomalous phase behaviors in systems of particles interacting through spherically-symmetric unbounded potentials. Our results show that an extremely weak softening of the interparticle repulsion, yielding a single nearest-neighbor separation, is able to originate a wide spectrum of unconventional features including reentrant melting, solid polymorphism, as well as thermodynamic, dynamic, and structural anomalies. These findings extend the possibility of anomalous phase behavior to a class of systems much broader than currently assumed.