Role of Metastable States in Phase Ordering Dynamics

TL;DR

This paper investigates how metastable intermediate phases can significantly alter phase separation dynamics, particularly by unbinding interfaces and impeding solid growth in a one-dimensional model.

Contribution

It introduces a theoretical framework using Cahn-Hilliard theory to analyze the impact of metastable phases on phase ordering and interface behavior.

Findings

Metastable phases can unbind interfaces during phase separation.

Unbinding of interfaces can slow down or hinder solid phase growth.

Criteria for interface unbinding depend on supersaturation levels.

Abstract

We show that the rate of separation of two phases of different densities (e.g. gas and solid) can be radically altered by the presence of a metastable intermediate phase (e.g. liquid). Within a Cahn-Hilliard theory we study the growth in one dimension of a solid droplet from a supersaturated gas. A moving interface between solid and gas phases (say) can, for sufficient (transient) supersaturation, unbind into two interfaces separated by a slab of metastable liquid phase. We investigate the criteria for unbinding, and show that it may strongly impede the growth of the solid phase.