The Au was evaporated onto the (100) cleavage plane of the halides under ultra-high vacuum. After deposition, the substrate was annealed, the Au crystallites became mobile, and underwent random walks on the surface. Some clusters collided and formed larger groups. The crystallite density decreased and the mean cluster radius increased with increasing annealing time. An analysis of the two-dimensional diffusion process furnished the diffusion coefficients of the crystallites (figure 5). These depended upon the substrate material, the substrate temperature and the cluster size. There appeared to be no effect of the crystallographic orientation of the crystallites upon their lateral mobility.

The Diffusion Process of Gold Crystallites on (100) Cleavage Planes of KBr, KCl and NaCl. G.Reiners: Thin Solid Films, 1986, 143[3], 311-20