From the ideal gas to an ideal glass: reversible path to random close packing

TL;DR

This paper presents a reversible thermodynamic pathway from an ideal gas to a random close packing (RCP) glass state, enabling unique characterization of RCP by preventing crystallization and heterogeneities.

Contribution

It introduces a well-defined, reversible route to RCP using a thermodynamic process that inhibits crystallization, advancing understanding of amorphous packing states.

Findings

Reproducible RCP state achieved via a rate process based on free volume.

Thermodynamic pathway prevents crystal nucleation, maintaining amorphous state.

Unique characterization of RCP enabled through the SCSO cell system.

Abstract

A reproducible RCP state is obtained by a well-defined rate process, which is first-order in free volume, starting from an equilibrium thermodynamic state of the hard-sphere fluid. The RCP state is also reproduced by a thermodynamic pathway that inhibits the frequent production of small crystal nucleites which can lead to heterogeneities at close packing. The simple-cubic single-occupancy (SCSO) cell system, in which crystallization is de facto prohibited, provides a reversible path all the way from the ideal gas to the ideal glass (RCP). By such a route, unique characterization of RCP becomes possible.