Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 29: Poster II

DY 29.72: Poster

Donnerstag, 28. Februar 2008, 16:00–18:00, Poster C

Role of ion-ion interaction for diffusion paths and residence sites in glassy electrolytes — •Egbert Zienicke, Christian Müller, and Philipp Maass — Institut für Physik, Technische Universität Ilmenau, 98684 Ilmenau, Germany

Properties of diffusion paths and residence sites for mobile ions in glassy elctrolytes are essential to understand ionic tranport in these complex materials. An important question is, whether the diffusion paths and residence sites can be determined from knowledge of the network structure, as e.g. provided by reverse Monte Carlo modelling of neutron or X-ray diffraction data. To study this question we analyze structures of a lithium silicate glasses obtained from molecular dynamics simulations [1]. We first check how far the mere network potential of the immobile ions determines the diffusion paths. Then we investigate the influence of the Coulomb interaction betweeen the mobile Li ions with the help of Monte Carlo simulations. Our results suggest that path properties are largely determined by the network, but that the location of residence sites is strongly influenced by Li-Li interactions.

In relation to this work it is necessary also to critically examine the reliability of the potential models for modified network glasses commonly used in molecular dynamics simulations. A new approach is presented to develop such models by means of electronic structure calculations based on disordered partial structures.

[1] C. Müller, E. Zienicke, S. Adams, J. Habasaki, and P. Maass, Phys. Rev. B 75, 014203 (2007).