Cooperativity and the Freezing of Molecular Motion at the Glass Transition
Condensed Matter journal club
Cooperativity and the Freezing of Molecular Motion at the Glass Transition
- Event time: 11:30am
- Event date: 13th December 2013
- Speaker: Professor Martin Evans (School of Physics & Astronomy, University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Event details
Abstract
The slowing down of molecular dynamics when approaching the glass transition generally proceeds much stronger than expected for thermally activated motions. This strange phenomenon can be formally ascribed to a temperature-dependent activation energy E(T). In the present work, via measurements of the third-order nonlinear dielectric susceptibility, we deduce the increase of the number of correlated molecules Ncorr when approaching the glass transition and find a surprisingly simple correlation of E(T) and Ncorr(T). This provides strong evidence that the noncanonical temperature development of glassy dynamics is caused by a temperature-dependent energy barrier arising from the cooperative motion of ever larger numbers of molecules at low temperatures.PRL 111 225702 (2013)
pdf version
Authors
Th. Bauer, P. Lunkenheimer, A. Loidl
About Condensed Matter journal club
Given the diversity of research in the CM group, chosen topics vary widely. We tend to stick to high-impact journals - Nature, Science, PNAS and PRL have been popular - but this is not prescriptive..