TY  - JOUR
AU  - Faraone, Antonio
AU  - Hong, Kunlun
AU  - Kneller, Larry R.
AU  - Ohl, Michael
AU  - Copley, John R. D.
TI  - Coherent dynamics of meta-toluidine investigated by quasielastic neutron scattering
JO  - The journal of chemical physics
VL  - 136
IS  - 10
SN  - 0021-9606
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2015-03972
SP  - 104502 -
PY  - 2012
AB  - The coherent dynamics of a typical fragile glass former, meta-toluidine, was investigated at the molecular level using quasielastic neutron scattering, with time-of-flight and neutron spin echo spectrometers. It is well known that the static structure factor of meta-toluidine shows a prepeak originating from clustering of the molecules through hydrogen bonding between the amine groups. The dynamics of meta-toluidine was measured for several values of the wavevector transfer Q, which is equivalent to an inverse length scale, in a range encompassing the prepeak and the structure factor peak. Data were collected in the temperature range corresponding to the liquid and supercooled states, down to the glass transition. At least two dynamical processes were identified. This paper focuses on the slowest relaxation process in the system, the α-relaxation, which was found to scale with the macroscopic shear viscosity at all the investigated Q values. No evidence of “de Gennes” narrowing associated with the prepeak was observed, in contrast with what happens at the Q value corresponding to the interparticle distance. Moreover, using partially deuterated samples, the dynamics of the clusters was found to be correlated to the single-particle dynamics of the meta-toluidine molecules.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000301664600023
DO  - DOI:10.1063/1.3691185
UR  - https://juser.fz-juelich.de/record/201678
ER  -