Regensburg 2019 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 54: Poster: Complex, Fluids, Glasses, Granular

DY 54.4: Poster

Donnerstag, 4. April 2019, 15:00–18:00, Poster B2

Investigation of the glassy dynamics of charged Lennard-Jones systems with molecular dynamics simulations — •Lukas Hecht, Robin Horstmann, and Michael Vogel — TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany

The explanation of the glass transition is one of the most challenging topics in physics of condensed matter. To get ahead, recent work investigated systematically altered water and silica variants in bulk and confinement to ascertain the glass transition behavior via molecular dynamics simulations [1]. A strong relation between the activation energy in the simple liquid regime at high temperatures and the glass transition temperature was found. Moreover, it proved useful to decompose the activation energy into a temperature independent part and a temperature dependent part associated with cooperative dynamics, which is an exponential function of temperature [2].

Since water and silica have a complex structure with prefered order, it is difficult to ascertain basic mechanisms behind the glass transition. Therefore, we focus on simpler systems, explicitly mixtures of charged Lennard-Jones atoms. We vary the mixing ratio of the atoms as well as their partial charges and analyze their dynamics in wide temperature ranges. In this way, it is possible to strongly vary the high-temperature activation energy and the glass transition temperature and, thus, to obtain further insights into their relation.

[1] J. Geske et al., Z. Phys. Chem., 2018, 232(7-8), pp 1187-1225

[2] B. Schmidtke et al., Phys. Rev. E, 2012, 86, 041507