Composition effect on shrinkage of hollow binary alloy nanospheres

In this paper, a hollow random binary alloy nanosphere and initially homogeneous is considered under the approximation that the radial dependence of the vacancy formation free energy can be neglected. On the basis of a theoretical description and kinetic Monte Carlo simulations it is shown that the steady-state condition for the atomic components is not achievable during its shrinkage at any composition when the ratio of the tracer diffusion coefficients D*ᴀ/D*ʙ not greater than two orders of magnitude. In the theoretical description, the dependence of the collapse time of the hollow random binary alloy nanosphere on the atomic fraction x of the faster diffusing species at x ≤ 0.5 can be estimated by using the geometric mean of the ratios of the atomic fluxes at self-diffusion and steady-state. At x > 0.5 the ratio of the atomic fluxes approaches the self-diffusion ratio as x increases.