Regensburg 2010 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 19: Synthesis of Nanostructured Films by Self-organization I (Focused Session)

DS 19.7: Topical Talk

Mittwoch, 24. März 2010, 12:15–12:45, H2

Synthesis of Nanostructured Films by Self-organization — •Hans Hofsäss — II. Physikalisches Institut, Universität Göttingen, Göttingen, Germany

Two approaches to achieve self-organized formation of nanostructured thin films will be discussed. In the first approach, nanocomoposite films are prepared by simultaneous deposition of two desired constitutents, e.g. the formation of metal-carbon nanocomposites by simultaneous metal and carbon ion deposition [1]. Depending on the phase diagram one would expect a homogeneous alloy or nanocomposite system. Instead, one often observes multilayered films with alternating metal and carbon layers. The formation of such layered films is explained by self-organization caused by surface segregation, clustering, sputtering and ion induced diffusion. A growth model taking into account these processes allows to predict the transition between self-organized multilayer formation and formation of homogeneous nanocomposites as function of ion energy and ion flux ratio. The second approach is surfactant sputtering [2], i.e. sputter erosion of a substrate, simultaneously exposed to a weak flux of surfactant atoms. Depending on the surfactant-substrate combination self-organized nanostructured ultrathin films are formed as a steady-state. This leads to the generation of novel surface patterns and surface nanostructures. Selected examples of will be discussed. [1] H. Hofsäss and K. Zhang, Appl. Phys. A: Mat. Sci. Proc. 92 (2008) 517 [2] I. Gerhards, H. Stillrich, C. Ronning, H. Hofsäss and M. Seibt, Phys. Rev. B70 (2004) 245418