Berlin 2008 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 29: Poster II
DY 29.69: Poster
Donnerstag, 28. Februar 2008, 16:00–18:00, Poster C
Modelling of susceptibility spectra of glass forming propylen carbonate with a schematic model of mode-coupling theory above and below Tc — •Markus Domschke1, Thomas Blochowicz1, Thomas Voigtmann2, and Bernd Stühn1 — 1TU Darmstadt, Germany — 2Deutsches Zentrum für Luft- und Raumfahrt, Germany
Recently the glass former propylen carbonate was investigated by a two-component schematic model of the extended mode-coupling theory (MCT). It was possible to describe the dynamic susceptibilities from microscopic frequencies down to the GHz range, but it was not successful to find a realistic model of the α peak and excess wing at the low-temperature regime [1,2]. Therefore we introduced a phenomenological frequency-dependent hopping parameter Δ(ω) to model the α process even below Tc. This leads to a proper description of measured data by dielectric spectroscopy and depolarized-light scattering in the whole frequency and temperature range, derived from a common density correlator.
[1] H Z Cummins, J. Phys.: Condens. Matter 17, 1457 (2005)
[2] W. Götze and Th. Voigtmann, Phys. Rev. E 61, 4133 (2000)