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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.10: Poster

Donnerstag, 11. März 2004, 16:00–18:00, Poster D

Vacancy model for the mixed alkali effect — •Robby Peibst, Stephan Schott, Hartmut Grille, and Philipp Maass — Institut für Physik, Technische Universität Ilmenau, Germany

In ionically conducting glasses, all properties associated with long-range ionic motion show large deviations from a simple additive behavior upon mixing of two different types of mobile ions. This phenomenon is called the mixed alkali effect and is of particular theoretical interest due to its crucial role for the general understanding of ion transport in glasses. Recent molecular dynamics simulations and further general considerations suggest that the number of vacant sites in the glassy network is rather small. Motivated by these findings and by taking into account the existence of different energies of the ion sites [3], we discuss possible szenarios to explain the mixed alkali effect by a vacancy mechanism.
[1] H. Lammert, M. Kunow, and A. Heuer, Phys. Rev. Lett. 90, 215901 (2003)
[2] J. Habasaki and Y. Hiwatari, Phys. Rev. B, in print
[3] Ph. Maass, J. Non-Cryst. Solids 255, 35 (1999)