Molecular dynamics simulations were made of the role played by vacancy diffusion in the surface ordering of (00l). It was found that vacancy diffusion proceeded preferentially by hopping along the [110] direction. Successive vacancy diffusion events induced an irreversible loss of surface order. These findings could be used to understand the order–disorder transition which occurred in the Cu3Au(00l) surface. It was found that the vacancy diffusion rate saturated quickly (in less than 1ns) and was correlated with the surface order parameter which already exhibited considerable disorder at 500K.

Vacancy Diffusion Driven Surface Rearrangement in the Cu3Au(001) and Ni3Al(001) Surfaces. C.E.Lekka, G.A.Evangelakis: Applied Surface Science, 2003, 205[1-4], 280-8