TY  - JOUR
AU  - Arbe, A.
AU  - Colmenero, J.
AU  - Alvarez, F.
AU  - Monkenbusch, M.
AU  - Richter, D.
AU  - Farago, B.
AU  - Frick, K. H.
TI  - Non-Gaussian nature of the alpha-relaxation of glass-forming polyisoprene
JO  - Physical review letters
VL  - 89
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-24202
SP  - 245701
PY  - 2002
N1  - Record converted from VDB: 12.11.2012
AB  - We report quasielastic neutron scattering experiments exploring the alpha relaxation in polyisoprene over an unprecedented range in momentum transfer. Corroborating and validating earlier molecular dynamics simulations, the measurements reveal a crossover from a Gaussian regime of sublinear diffusion to a strongly non-Gaussian regime at short distances. We show that a consistent interpretation in terms of a distribution of finite jumps underlying the alpha process is possible. This model leads to a time-dependent non-Gaussian parameter exhibiting all features revealed so far from various simulations.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000179484700027
DO  - DOI:10.1103/PhysRevLett.89.245701
UR  - https://juser.fz-juelich.de/record/24202
ER  -