A robust comparison of dynamical scenarios in a glass-forming liquid. Issue 5 (15th January 2016)

• Record Type: Journal Article
• Authors: Vispa, Alessandro; Busch, Sebastian; Tamarit, Josep Lluis; Unruh, Tobias; Fernandez-Alonso, Felix; Pardo, Luis Carlos
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 5(2016)
• Page Start: 3975
• Page End: 3981
• Publication Date: 2016-01-15
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp05143f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We use Bayesian inference methods to provide fresh insights into the sub-nanosecond dynamics of glycerol, a prototypical glass-forming liquid. Abstract : We use Bayesian inference methods to provide fresh insights into the sub-nanosecond dynamics of glycerol, a prototypical glass-forming liquid. To this end, quasielastic neutron scattering data as a function of temperature have been analyzed using a minimal set of underlying physical assumptions. On the basis of this analysis, we establish the unambiguous presence of three distinct dynamical processes in glycerol, namely, translational diffusion of the molecular centre of mass and two additional localized and temperature-independent modes. The neutron data also provide access to the characteristic length scales associated with these motions in a model-independent manner, from which we conclude that the faster (slower) localized motions probe longer (shorter) length scales. Careful Bayesian analysis of the entire scattering law favors a heterogeneous scenario for the microscopic dynamics of glycerol, where molecules undergo either the faster and longer or the slower and shorter localized motions.