Regensburg 2007 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 4: Liquid and amorphous materials II

MM 4.4: Vortrag

Montag, 26. März 2007, 12:30–12:45, H4

Self-assembly of monatomic complex crystals and quasicrystals with a double-well potential — •Michael Engel and Hans-Rainer Trebin — Universität Stuttgart, Institut für Theoretische und Angewandte Physik, 70550 Stuttgart

For the study of crystal growth and dynamics a simple two-dimensional monatomic model system with three parameters is introduced. Depending on the value of the parameters several complex crystals, a decagonal quasicrystal, and a dodecagonal quasicrystal are stabilized in thermal equilibirum. They show up in the phase diagram of the system, which we calculate using molecular dynamics simulations. The observed crystals can have unit cells larger than the interaction radius. When growing the complex (quasi-)crystals from the liquid state, a continuous amelioration of the structure by diffusion processes is observed. This is accomplished by discrete atomic jumps over well-defined jump distances. For the investigation an interactive virtual lab is used, that allows a direct observation and control of the simulation dynamics.