Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 3: Liquid Crystals and Polar Fluids
CPP 3.7: Vortrag
Montag, 25. Februar 2008, 11:45–12:00, C 264
Disappearance of ferromagnetic ordering in nanoconfined dipolar fluids — •Sabine H.L. Klapp1,2 and R. Andreea Trasca2 — 1Institute of Theoretical Physics, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany — 2Stranski-Laboratorium of Physical and Theoretical Chemistry, TU Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
We present Monte-Carlo (MC) simulation results for dipolar fluid films under strongly coupled conditions where the bulk fluid [1] and films of mesoscopic thicknesses [2] display ferromagnetic ordering. We demonstrate that the ordering persists down to nanoscopic wall separations where the system consists of only four monolayers [3]. For smaller thicknesses we observe stripe-like defects (domains) and finally the breakdown of ferromagnetic ordering for systems close to the two-dimensional limit [3,4]. The results for the liquid phase are supported by MC calculations starting from quasi-crystalline soft-sphere configurations. Our findings are relevant for systems of magnetic colloids but also for the ordering behavior of thin solid-like magnetic films.
[1] D. Wei and G. N. Patey, Phys. Rev. Lett. 68, 2043 (1992)
[2] S. H. L. Klapp and M. Schoen, J. Chem. Phys. 117, 8050 (2002).
[3] R. A. Trasca and S. H. L. Klapp, in preparation.
[4] S. H. L. Klapp, Mol. Sim. 32, 609 (2006).