Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 47: Heterogeneous Nucleation and Microstructure Formation (related to SYMF, jointly with MM)

CPP 47.8: Vortrag

Freitag, 18. März 2011, 12:15–12:30, ZEU 160

Homogeneous and heterogeneous nucleation in phase field crystal models studied by the simplified string method — Rainer Backofen and •Axel Voigt — Institut für Wissenschaftliches Rechnen, TU Dresden, Dresden, Germany

The phase field crystal (PFC) model is an approximation to the classical density functional theory of liquid and solids. In recent years it has been shown that with some modification PFC gives decent descriptions of colloids or metals. We investigate a PFC model for homogeneous and heterogeneous nucleation at unstructured walls. We will show, that in order to include wall interactions the density in the classical PFC model has to be bound from below. This can be achieved by introducing a density dependent mobility or an additional density dependent potential. Thus, the wall interaction maybe tuned from wetting to non-wetting conditions. The nucleation process is analyzed directly by the Simplified String Method and the minimal stable nucleus is defined. We see that the nucleation path deviates from that one assumed in classical nucleation theory. In particular the minimal stable nucleus is not in the bulk state. Thus, the nucleation barrier is decreased.