Vacancy-mediated suppression of phase separation in a model two-dimensional surface alloy by the difference of the atomic jump rates

Abstract

A vacancy-mediated collective diffusion model is used to compute a thermally-induced (spinodal) phase separation in a typical fcc bi-metallic surface alloy at low median concentration of vacancies, focusing on the effect of the ratio, $\Gamma ={\Gamma }_A/{\Gamma }_B$, of the jump rates to the vacant sites of the two types of atoms. The model is formulated for the diffusion of one atomic species and vacancies, employing the kinetic transport coefficients derived by Moleko \emph{et al.} (Phil. Mag. A 59, 141 (1989)). It is demonstrated that for A${}_{0.7}$B${}_{0.3}$ alloy, $\Gamma \sim 50$ results in suppression of phase separation, whereas very small $\Gamma$ values result in mild phase separation (i.e., the suppression is incomplete).

References in corpus (4)

• A conductive topological insulator with colossal spin Hall effect for ultra-low power spin-orbit-torque switching
• Nothing moves a surface: vacancy mediated surface diffusion
• Topological Weyl semimetals in $\mathrm{Bi}$${}_{1-x}$$\mathrm{Sb}$${}_x$ alloys
• Directed long-range transport of a nearly pure component atom clusters by the electromigration of a binary surface alloy

Cited by in corpus (1)

• Moiré-regulated composition evolution kinetics of bicomponent nanoclusters