Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 29: Crystallisation, Nucleation and Self assembly

CPP 29.4: Vortrag

Mittwoch, 28. März 2012, 16:15–16:30, C 243

Simulations of colliodial rods on a 2D quasicrystalline substrate — •Philipp Kählitz and Holger Stark — Institut für theoretische Physik, TU Berlin

Quasicrystals are structures with long-range positional and orientational order. However, they cannot be periodic since they possess rotational symmetries such as 5- or 10-fold axis that are forbidden for conventional crystals. These structures lead to new and unique features of matter. Therefore, a lot of effort has recently been initiated to grow atomic quasicrystals on quasicrystalline surfaces. To mimic this situation, 2D light-interference patterns have been used tostudy the phase behavior of micron-sized colloidal particles in a 2D quasicrystalline potential and new ordered phases have been identified [1,2]. This talk discusses how colloidal rods order in a quasicrystalline decagonal substrate potential. We use Monte-Carlo simulations tostudy the phase behavior of hard spherocylinders and identify, in particular, a novel decagonal phase made by clusters of aligned rods at high densities. In the low density case the behavior of the rods is similar to the previously studied hard needles [3]. We map out phase diagrams as a function of strength of the surface potential and the particle density for different rod lengths and diameters.

[1] Mikhael et al., Nature (London) 454, 501 (2008)

[2] M. Schmiedeberg and H. Stark, PRL 101, 218302 (2008)

[3] P. Kählitz and H. Stark, submitted.