Kinetics of Modulated and Ordered Structures in CuAu

TL;DR

This paper presents a continuum model based on an atomistic Hamiltonian to study the ordering kinetics and formation of modulated and ordered structures in CuAu, revealing metastability effects and complex microstructures.

Contribution

It introduces a continuum modeling approach for CuAu ordering kinetics, highlighting metastability and microstructure formation not previously detailed.

Findings

Metastability of the modulated phase hinders ordered superlattice formation.

Formation of lamellar and labyrinthine structures observed.

Detailed description of low and high temperature ordered states.

Abstract

A continuum model derived from an atomistic Hamiltonian is used to examine the ordering kinetics in CuAu. A detailed description of the formation of the low and high temperature ordered and modulated superlattice states is given. The metastability of the modulated phase at low temperatures is shown to severely hinder creation of the ordered superlattice. Formation of the modulated superlattice is shown to results in interesting lamellar and labyrinthine structures.