Regensburg 2010 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 30: Posters II
DY 30.10: Poster
Donnerstag, 25. März 2010, 16:00–18:00, Poster C
Varying Coulomb Trapping of Network Forming Units and the Mixed Glass Former Effect — •Michael Schuch1,2, Christian Robert Müller2, and Philipp Maass1,2 — 1Fachbereich Physik, Universität Onsabrück, 49069 Osnabrück, Germany — 2Institut für Physik, Technische Universität Ilmenau, 98684 Ilmenau, Germany
Mixing of two types of glass formers in ion conducting glasses can lead to strong enhancements of ionic conductivities, a phenomenon commonly referred to as the Mixed Glass Former Effect (MGFE). A theory for the MGFE is presented which allows one to describe the change of concentrations of network forming units upon mixing and associated changes in Coulomb trapping energies. Using this structural information the change of the conductivity activation energies is calculated by means of percolation theory and Monte Carlo simulations. Fits of the theory to experiments on a borophosphate system yield good agreement with the measured data both for the concentration variation of the units and the variation of the activation energy.