Berlin 2005 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 35: Glasses I (joint session DF/DY)
DY 35.11: Vortrag
Montag, 7. März 2005, 12:45–13:00, TU A060
Molecular reorientation dynamics of a supercooled molecular liquid, ionic liquid, and liquid crystal: a comparison — •Alexander Brodin, Alexei Pugachev, and Ernst Rössler — LS Experimentalphysik II, Universität Bayreuth
We report on a comparative depolarized light scattering study of three rather different supercooled systems: glycerol (molecular liquid), LiCl:5H2O (ionic liquid) and 5CB (nematic liquid crystal), at temperatures that cover the range from a deeply supercooled glassy state to a high temperature equilibrium liquid state, including the isotropic and supercooled nematic phases of 5CB. In molecular systems composed of anisotropic molecules, the main contribution to the depolarized light scattering comes from molecular reorientations - unrestricted and isotropic in the case of an isotropic liquid (glycerol, H2O), and restricted about the director in the case of a liquid crystal (5CB). Despite the different nature of the studied systems, they all exhibit qualitatively similar spectra and temperature evolution thereof.