HELIUM DIFFRACTION STUDY OF THE NUCLEATION AND GROWTH OF PALLADIUM CLUSTERS ON MGO (100)

Helium diffraction is used for the first time to study the nucleation and growth of three-dimensional metallic clusters on a crystalline sub strate. It is shown that from the attenuation of the first order diffr action peak from the MgO substrate it is possible to derive the growth rate and the nucleation kinetics of the Pd clusters. Transmission ele ctron microscopy (TEM) observation of the final deposit allows one to determine the width of the diffuse scattering zone around the clusters . The first results obtained at two different substrate temperatures a re analysed following the atomistic theory of nucleation and growth.