Dresden 2011 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 42: Poster I: Progress in Micro- and Nanopatterning: Techniques and Applications (jointly with O); Spins in Organic Materials; Ion Interactions with Nano Scale Materials; Organic Electronics and Photovoltaics; Plasmonics and Nanophotonics (jointly with HL and O); High-k and Low-k Dielectrics (jointly with DF); Organic Thin Films; Nanoengineered Thin Films; Layer Deposition Processes; Layer Properties: Electrical, Optical, and Mechanical Properties; Thin Film Characterisation: Structure Analysis and Composition; Application of Thin Films
DS 42.52: Poster
Mittwoch, 16. März 2011, 15:00–17:30, P1
Broadband dielectric spectroscopic studies on 4- heptan -4'- isothiocyanatobiphenyl (7BT) in confining geometry. — •Malgorzata Jasiurkowska1, Emmanuel U. Mapesa1, Ciprian Iacob1, Periklis Papadopoulos1, Friedrich Kremer1, and Maria Massalska-Arodz2 — 1Institute of Experimental Physics I, University of Leipzig, 04103 Leipzig, Germany — 2The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
Band Dielectric Spectroscopy is employed to investigate 4-heptan-4'- isothiocyanatobiphenyl (abbreviated as 7BT) in one- and two-dimensional confinement (in the frequency range 0.1 Hz to 10-6 Hz). In bulk, only one liquid crystalline phase, the smectic E (SmE) phase with orthorhombic arrangement within the molecular layers is observed. The bulk dielectric properties of the nBT compounds are now well understood. For measurements under one-dimensional confinement, ultrathin films of 7BT prepared by spin-coating method are measured in the nanostructured-electrode configuration. In contrast to bulk dielectric spectra where only one process is observed in the low frequency regime, an additional process appears. Dynamic properties of 7BT are also studied in nanoporous silica membranes. It is observed that the crystallization temperature is significantly reduced in comparison to the value for bulk 7BT. Moreover, beside the relaxation around short axis, two extra processes are observed. The influence of pore size on molecular dynamics will be discussed.