Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: Focus: Magnetic Soft Matter II

CPP 20.2: Vortrag

Mittwoch, 25. März 2009, 10:00–10:15, ZEU 222

Structure of ferrofluid nanofilms in homogeneous magnetic fields — •Jelena Jordanovic and Sabine H. L. Klapp — Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin

We report molecular dynamic simulations for a model Stockmayer fluid confined between two plane, parallel walls and subject to an external homogeneous field. The occurring layers, which are characteristic for fluid nanofilms, can be controlled via the field such that for an appropriate film thickness a new layer is created in a perpendicular field while in a parallel field one layer can be destroyed [1]. This field-controlled layering modulation as well as formation of hexagonal or labyrinth in-plane patterns have also been observed in experiments [2,3] and are a promising route for designing novel materials. In our study we examine in detail the dependence of the field-induced structural changes in-plane and normal to the film surfaces on the thermodynamic state [4] for both field directions. Also, we inspect the influence of the attractive contribution of the Lennard-Jones potential on the structural behavior in field. Additionally we investigate a mono- to bilayer transition induced via a perpendicular field to relate our findings to quasi-two-dimensional systems.

[1] J. Jordanovic and S. H. L. Klapp, Phys. Rev. Lett. 101, 038302 (2008).

[2] A. Vorobiev et.al. Phys. Rev. Lett. 93, 267203 (2004).

[3] V. Germain et.al. J. Phys. Chem B 109, 5541 (2004).

[4] J. Jordanovic and S. H. L. Klapp, submitted.