Coherent Dynamics of meta-Toluidine Investigated by QuasiElastic Neutron Scattering

Published

March 14, 2012

Author(s)

Antonio Faraone, Kunlun Hong, Larry Kneller, Michael Ohl, John R. Copley

Abstract

The coherent dynamics of a typical fragil 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 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 staets, 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 wit the macroscopic shear viscosity at 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-toludine molecules.

Citation

Journal of Chemical Physics

Volume

136

Issue

10

Pub Type

Journals

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Keywords

Glass transition, neutron scattering, dynamics

Citation

Faraone, A. , Hong, K. , , L. , Ohl, M. and Copley, J. (2012), Coherent Dynamics of meta-Toluidine Investigated by QuasiElastic Neutron Scattering, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909774 (Accessed December 14, 2024)