Regular Article

Excess wing in glass-forming glycerol and LiCl-glycerol mixtures detected by neutron scattering

¹ Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at SNS-Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, 37831, Oak Ridge, TN, USA
² Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747, Garching, Germany
³ Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135, Augsburg, Germany
⁴ SNS, Neutron Sciences Directorate, Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, 37831, Oak Ridge, TN, USA

^* e-mail: s.gupta@fz-juelich.de

Received: 31 July 2014
Revised: 22 October 2014
Accepted: 2 December 2014
Published online: 22 January 2015

Abstract

The relaxational dynamics in glass-forming glycerol and glycerol mixed with LiCl is investigated using different neutron scattering techniques. The performed neutron spin echo experiments, which extend up to relatively long relaxation time scales of the order of 10ns, should allow for the detection of contributions from the so-called excess wing. This phenomenon, whose microscopic origin is controversially discussed, arises in a variety of glass formers and, until now, was almost exclusively investigated by dielectric spectroscopy and light scattering. Here we show that the relaxational process causing the excess wing can also be detected by neutron scattering, which directly couples to density fluctuations.