The deposition, and very first steps of Ag nucleation and growth, were studied on Pd(100) by means of thermal energy atom scattering. It was found that the technique was a very sensitive and non-perturbing probe of surface point defects, and permitted the  in situ  and real-time monitoring of deposition. The form of the specularly reflected He signal, as a function of coverage and surface temperature, was compared with theoretical curves which had been predicted by solving a system of rate equations that described the formation and destruction of clusters during deposition. Analysis of the experimental data yielded an activation energy of 0.37eV and a pre-exponential factor of 8 x 109/s for Ag on Pd(100). It was also found that all Ag atoms which impinged upon a zone of 0.61nm around an adatom on the surface were captured by the latter at surface temperatures which were well below the onset of thermally activated mobility. This phenomenon was tentatively attributed to the combined effect of transient and neighbor-driven mobility.

C.Félix, G.Vandoni, W.Harbich, J.Buttet, R.Monot: Physical Review B, 1996, 54[23], 17039-50