Dynamics of confined glass-forming systems observed by neutron scattering

• Published in: Physica. B, Condensed matter Vol. 350; no. 1; pp. E1115 - E1118
• Main Authors: Zorn, Reiner, Frick, Bernhard, Hartmann, Lutz, Kremer, Friedrich, Schönhals, Andreas, Richter, Dieter
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-07-2004
• Subjects: Confinement; Glass transition; Glass transition; 61.20.Lc; Confinement; 64.70.Pf; 61.41.+e
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2004.03.303

In this article, results on the microscopic dynamics of a low-molecular glass former and a polymer confined in nanoporous silica obtained by inelastic neutron scattering are presented. By combining time-of-flight spectroscopy and backscattering spectroscopy we are able to cover a large dynamical range, from the low-frequency vibrations to the α relaxation. The most prominent effect was observed on the “boson peak” in the vibrational spectrum. A strong reduction of the modes at lowest frequencies could be observed in both cases. The main effect on the α relaxation is a broadening for the salol system. For the polymeric system a difference of the confinement influence on the methyl-group rotation and the α relaxation can be detected from a first qualitative interpretation of the data.