Complex Phase Behavior of Repulsive Step Potential Systems in Three Dimensions

TL;DR

This study uses computer simulations to explore the complex phase diagram of a purely repulsive isotropic potential system in three dimensions, revealing unusual features like isostructural transitions and amorphous phases.

Contribution

It provides a detailed phase diagram of the repulsive step potential system, highlighting novel features such as maxima and minima on the melting curve and amorphous phases.

Findings

Maxima and minima on the melting curve identified.

Presence of two isostructural crystalline phases separated by an amorphous phase.

Structural FCC-BCC transition observed at high densities.

Abstract

The comprehensive computer simulation study of the phase diagram of the repulsive step potential system in three dimensions is represented. We show that the system with a simple purely repulsive isotropic potential demonstrates a number of unusual features. The maxima and minima on the melting curve are found for some regions of potential parameters. It is shown that the phase diagram in $\rho-T$ plane includes two isostructural crystalline parts separated by the disordered phase which is amorphous at low enough temperatures. Phase diagram in the (P-T) plane shows that the transition to the amorphous state occurs approximately along the extrapolated spinodals. Structural FCC-BCC phase transition is found at high densities.