Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 84: Glasses and Glas transition (joint session DY/CPP)

CPP 84.6: Vortrag

Freitag, 16. März 2018, 11:15–11:30, BH-N 334

Secondary Relaxation Dynamics Observed by Photon-Correlation-Spectroscopy — •Till Böhmer, Jan Gabriel, Andreas Helbling, Florian Pabst, and Thomas Blochowicz — TU Darmstadt, Institut für Festkörperphysik, Germany

Secondary relaxation processes in simple molecular glass formers have been a long-standing topic in research of supercooled liquids and amorphous solids. In particular understanding the mechanism behind Johari-Goldstein-β-relaxation is considered to be important, because it originates from the dynamic of the entire molecule and is expected to be a universal feature of the glass-transition.

To obtain a new perspective, photon-correlation-spectroscopy (PCS) was utilized to examine reorientational dynamics in various monohydroxy alcohols. After improvements regarding the experimental setup secondary relaxation processes were successfully resolved in PCS. By comparing the results of light scattering experiments with those of broadband dielectric spectroscopy, focusing on the differences in amplitude and shape of the respective processes, insight on the mechanism behind the JG-β-relaxation can be gained.