Phase Separation Kinetics in a Model with Order-Parameter Dependent Mobility

TL;DR

This study uses 2D simulations to analyze phase separation kinetics with order-parameter dependent mobility, revealing universal scaling behavior similar to the Cahn-Hilliard equation, even with surface diffusion mechanisms.

Contribution

It demonstrates that the structure factor scaling function is universal across different mobility dependencies, challenging existing theories on bulk diffusion's role.

Findings

Structure factor exhibits dynamical scaling

Scaling function matches Cahn-Hilliard predictions

Universality holds even with surface diffusion

Abstract

We present extensive results from 2-dimensional simulations of phase separation kinetics in a model with order-parameter dependent mobility. We find that the time-dependent structure factor exhibits dynamical scaling and the scaling function is numerically indistinguishable from that for the Cahn-Hilliard (CH) equation, even in the limit where surface diffusion is the mechanism for domain growth. This supports the view that the scaling form of the structure factor is "universal" and leads us to question the conventional wisdom that an accurate representation of the scaled structure factor for the CH equation can only be obtained from a theory which correctly models bulk diffusion.