STM observation of cluster size dependence of HOPG surface damages induced by energetic Si-n and Ge-n clusters

Samples of highly oriented pyrolytic graphite (HOPG) were irradiated by Si-n (n = 1, 2, 3, 4, 5) with energy of 300 keV/atom and Ge-n (n = 1, 2, 3) with energy of 500 keV/atom at perpendicular incidence and at a fluence of 5 x 10(12) projectiles/cm(2), respectively. The observations by scanning tunneling microscopy (STM) clearly show a non-linear effect of the average damage area on the surface induced by clusters of different size. The dependence of the relative radiation damage on the cluster size follows a n(1.47) law for Si irradiation and a n(1.1) law for Ge irradiation, respectively. (c) 2005 Elsevier B.V. All rights reserved.Instruments & InstrumentationNuclear Science & TechnologyPhysics, Atomic, Molecular & ChemicalPhysics, NuclearSCI(E)EI0ARTICLE2373-37624