2021/01/08 by L. Hecht, R. Horstmann, B. Liebchen +1
Chemistry · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Binary number #Fragility #Glass properties and applications #Glass transition #Isochoric process #Material Dynamics and Properties #Molecular dynamics #Particle (ecology) #Relaxation (psychology) #Slowdown #Supercooling #cond-mat.soft
paper · pdf · doi:10.1063/5.0031417
published as J. Chem. Phys. 154, 024501 (2021) · This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Chem. Phys. 154, 024501 (2021) and may be found at https://doi.org/10.1063/5.0031417
openalex publication_date 2021/01/08 · openalex created_date 2021/01/18 · arxiv created 2021/03/01 · arxiv updated 2021/03/02 · openalex updated_date 2026/08/05
Experimental studies of the glassy slowdown in molecular liquids indicate that the high-temperature activation energy E∞ of glass-forming liquids is directly related to their glass transition temperature Tg. To further investigate such a possible relation between high- and low-temperature dynamics in glass-forming liquids, we analyze the glassy dynamics of binary mixtures using molecular dynamics simulations. We consider a binary mixture of charged Lennard-Jones particles and vary the partial charges of the particles and, thus, the high-temperature activation energy and the glass transition temperature of the system. Based on previous results, we introduce a phenomenological model describing relaxation times over the whole temperature regime from high temperatures to temperatures well inside the supercooled regime. By investigating the dynamics of both particle species on molecular and diffusive length scales along isochoric and isobaric pathways, we find a quadratic charge dependence of both E∞ and Tg, resulting in an approximately constant ratio of both quantities independent of the underlying observable, the thermodynamic ensemble, and the particle species, and this result is robust against the actual definition of Tg. This generic relation between the activation energy and the glass transition temperature indicates that high-temperature dynamics and the glassy slowdown are related phenomena, and the knowledge of E∞ may allow us to approximately predict Tg.