Effect of the vacancy interaction on the antiphase domain growth process in a two dimensional binary alloy

TL;DR

This study uses Monte Carlo simulations to explore how vacancies affect antiphase domain growth in a binary alloy, revealing different growth behaviors depending on vacancy interactions.

Contribution

It introduces a model incorporating vacancy interactions via a biquadratic coupling parameter and analyzes their impact on domain growth dynamics.

Findings

Vacancies tend to concentrate on antiphase boundaries.

Different vacancy interaction regimes lead to distinct growth laws.

Growth can be anisotropic, standard, or slowed depending on K.

Abstract

The influence of diffusing vacancies on the antiphase domain growth process in a binary alloy is studied by Monte Carlo simulations. The system is modelled by means of a Blume-Emery-Griffiths hamiltonian with a biquadratic coupling parameter K controlling the microscopic interactions between vacancies. We obtain that, independently of K, the vacancies exhibit a tendency to concentrate on the antiphase boundaries. This gives rise to an effective interactions between movin interfaces and diffusing vacancies which strongly influences the domain growth process. One distinguishes three different behaviours: i) for K<1 the growth is anisotropic and can be described by algebraic laws with exponents lower than 1/2, ii) for K=1 we find standard Allen-Cahn growth and iii) for K>1 the growth is slown down but still curvature driven.