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DF: Dielektrische Festkörper
DF 4: Gl
äser Ib (gemeinsam FV DF/DY)
DF 4.6: Vortrag
Dienstag, 25. März 2003, 11:30–11:45, HSZ/403
Complete identification of alkali sites in ion conducting glasses: a computer study — •Andreas Heuer, Magnus Kunow, and Heiko Lammert — Inst. f. Phys. Chemie, WWU Münster
The available sites for ions in a typical disordered ionic conductor are determined. For this purpose we devised a straightforward algorithm which via cluster analysis identifies these sites from long time ionic trajectories below the glass transition. This is exemplified for a lithium silicate glass (Li2O)x(SiO2)(1−x) for x = 0.5 and x = 0.1. We find that the number of sites is only 2% for x = 0.5 and 9% for x = 0.1 larger than the number of ions. This result suggests that a theoretical description of the dynamics in terms of mobile vacancies is most appropriate. Furthermore identification of the ionic sites allows one to obtain detailed characteristics of the ionic motion, e.g. quantification of correlated forward-backward motion.