Dresden 2009 – wissenschaftliches Programm

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SYSO: Symposium Self-organizing Surfaces and Interfaces

SYSO 1: Self-Organizing Surfaces and Interfaces I

SYSO 1.1: Hauptvortrag

Mittwoch, 25. März 2009, 14:00–14:30, BAR SCHÖ

Pattern formation in epitaxial growth and ion beam erosion — •Thomas Michely — II. Physikalisches Institut, Universität zu Köln, Germany

In this talk I will discuss three examples for self organisation on solid surfaces under conditions far from thermodynamic equilibrium. The first example relates to cluster lattice formation on a graphene moiré, a situation where adding under non equilibrium conditions the same particles as those forming one system phase causes a dramatic amplification of a spatial inhomogenity in the second system phase which in turn gives rise to a highly ordered and spontaneous arrangement of the added particles. The second example relates to crystal growth. The competition of random deposition and specific diffusion mechanisms leads to a self organized morphology of mounds. The characteristic length scales displayed allow one to read the fundamental atomistic parameters of diffusion from the pattern. At proper growth conditions a growth bifurcation takes place, where dependening on whether a specific feedback mechanism was turned on or not the system displays patches of qualitatively different structure. Finally we briefly address the topic of self organisation of ion beam eroded surfaces, which for crystalline substrate may be considered as the inverse process of crystal growth.