Dresden 2003 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 5: Gl
äser II (gemeinsam FV DF/DY)

DF 5.5: Vortrag

Dienstag, 25. März 2003, 15:45–16:00, HSZ/403

Reorientation dynamics in a supercooled plastic crystal studied by 2H NMR spectroscopy — •Sorin A. Lusceac, Peter Medick, Ingmar Roggatz, and Ernst Roessler — Universitaet Bayreuth, Lehrstul Experimentalphysik II, Universitaetstrasse 30, 95440 Bayreuth, Germany

Supercooled plastic crystals are simple systems for the study of glass transition phenomenon. Cyanoadamantane exhibits a plastically crystalline phase, which can be sufficiently supercooled allowing for extensive deuterium NMR studies (including line shape analysis and 2D experiments). We demonstrate that the molecules perform a 90-degree jump motion reflecting the symmetry of the cubic lattice. The degree of non-Debye behaviour of the orientation correlation function is small although the nature of the dynamics is collective. The results are compared with those from dielectric relaxation investigations.