"Probing Relation Phenomena on Glass Formers by IXS"
Presented by Alessandro Cunsolo
Tuesday, April 2, 2013, 11 am
Seminar Room, Bldg. 725
Relying upon the support of videos, it will be illustrated in depth the concept of viscoelasticity and how this intriguing property can be probed by Inelastic X Ray Scattering (IXS) at mesoscopic scales. It will be shown how theories based upon the memory function formalism can be successfully used to interpret IXS spectra of a prototype glass former (liquid glycerol) gaining valuable insight on its relaxational behavior. Based upon a comparison with independent ultrasound absorption measurements, the relevant phenomenological aspects of two classes of relaxations, microscopic and structural, will be finally discussed. In particular it will be demonstrated that the latter relaxation process has a characteristic timescale ranging in the sub-picosecond, systematically decreasing upon increasing the wave-vector and rather insensitive to pressure changes.