SCATTERING AND DEPOSITION OF MASS-SELECTED ANTIMONY CLUSTERS

Positively charged antimony cluster ions (Sb-n(+): 2 < n < 13) have be en scattered from the surface of highly oriented pyrolythic graphite ( HOPG) at energies up to 350 eV. Main fragmentation channels for the po sitively charged clusters are the formation of neutral Sb-2- and Sb-4- and charged Sb-3(+)-, Sb-5(+)- and Sb-7(+)- species. The stability of these products can be understood in the framework of the polyhedral s keletal electron pair theory. STM-images taken after the scattering of a mass selected cluster at a predefined energy from HOPG show the for mation of islands with a diameter of about 30 to 40 Angstrom. The isla nds are assumed to be formed by statistical diffusion of the collision products on the substrate surface. The number density of islands corr elates well with the measured scattering efficiencies and the cluster intensity in the beam.