J. Colmenero et al., CROSSOVER FROM DEBYE TO NON-DEBYE DYNAMICAL BEHAVIOR OF THE ALPHA-RELAXATION OBSERVED BY QUASI-ELASTIC NEUTRON-SCATTERING IN A GLASS-FORMING POLYMER, Physical review letters, 71(16), 1993, pp. 2603-2606
The dynamics of a very fragile glass-forming polymer is studied by tim
e of flight neutron scattering in a time scale from 10(-13) to 10(-11)
s. We observe a crossover from a Debye-like to a non-Debye behavior a
t a characteristic time which is effectively independent of temperatur
e and momentum transfer Q. We also confirm the results previously obta
ined about the non-Debye alpha relaxation in a different time scale (1
0(-11) to 10(-8) s). The results here reported open a new outlook for
understanding the fast dynamics of glass-forming systems.