Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: POSTERS Colloids, Nanoparticles and Aggregates

CPP 21.12: Poster

Mittwoch, 27. Februar 2008, 16:00–18:30, Poster A

Colloidal Adsorbate Structures on Quasicrystaline Light Fields — Jules Mikhael, •Laurent Helden, and Clemens Bechinger — 2. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany.

Quasicrystals are unusual materials since they exhibit no periodic structure but retain true long range order. Spontaneous formation of quasicrystals is typically only observed in rather complex metal alloys, for instance i-AlPdMn or d-AlNiCo, and strongly depends on the specific chemical composition. One way for forming monoatomic quasicrystalline structures is to use the surface of the quasicrystals as templates for adsorbed monolayers. Here we report a real space investigation of the phase behavior of micron-sized colloidal particles adsorbed onto a quasicrystalline decagonal substrate created by interfering five laser beams. For intermediate substrate strength a remarkably stable phase is found revealing likewise crystalline and quasicrystalline characteristics. It can be described by the Archimedean (3.3.3.4.4) tiling which is intersected by double rows of triangular tiles arranged in a Fibonacci sequence. The results on this model system open a route to identify the primordial parameters for the formation of pseudomorphic monoatomic quasicrystals.