Dynamics of Ordering in Alloys with Modulated Phases

TL;DR

This paper develops a theoretical model to study the dynamics of ordering in alloys with modulated phases, highlighting effects of non-linearities and elastic lattice interactions on growth kinetics.

Contribution

It introduces a novel model resembling the Swift-Hohenberg equation for alloy ordering, extending beyond standard theories to include elastic effects and simulation-ready Hamiltonians.

Findings

Early-stage growth kinetics analyzed and compared to Cahn-Hilliard theory.

Non-linearities significantly affect growth dynamics.

Elastic lattice effects introduce new qualitative behaviors.

Abstract

This paper presents a theoretical model for studying the dynamics of ordering in alloys which exhibit modulated phases. The model is different from the standard time-dependent Ginzburg-Landau description of the evolution of a non-conserved order parameter and resembles the Swift-Hohenberg model. The early-stage growth kinetics is analyzed and compared to the Cahn-Hilliard theory of continuous ordering. The effects of non-linearities on the growth kinetics are discussed qualitatively and it is shown that the presence of an underlying elastic lattice introduces qualitatively new effects. A lattice Hamiltonian capable of describing these effects and suitable for carrying out simulations of the growth kinetics is also constructed.