Study of the glass transition order parameter in amorphous polybutadiene by incoherent neutron scattering |
| |
Authors: | B. Frick D. Richter W. Petry U. Buchenau |
| |
Affiliation: | (1) Institut Laue-Langevin, Avenue des Martyrs 156X, F-38042 Grenoble, France;(2) Institut für Festkörperforschung, Kernforschungsanlage Jülich, Postfach 1913, D-5170 Jülich 1, Federal Republic of Germany |
| |
Abstract: | The temperature dependent elastic incoherent scattering from a glass forming polybutadiene was studied using high resolution neutron spectroscopy. This elastic scattering measures directly the non-ergodicity order parameter of the glass transition. We observed an anomalous decrease of this scattering setting in around 30 K below the thermodynamic glass transition,Tg, the temperature dependence of which is in agreement with the square root ofT prediction of the mode coupling approach. The critical temperature of 220 K lies about 30 K aboveTg. The missing elastic intensity reappears as inelastic scattering in the 1 meV range. Within the eV resolution of the backscattering spectrometer no quasielastic scattering can be detected up to 20 K aboveTg. The observed inelastic scattering may be interpreted as resulting from a continous shift of the density of states towards low frequencies as a consequence of a general softening of the structure. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|