Berlin 2008 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 6: Glasses I (joint session DF/DY)
DF 6.10: Vortrag
Dienstag, 26. Februar 2008, 12:00–12:15, EB 407
Collective atomic dynamics and relaxation processes in Al2O3 melt — •Sandro Jahn1 and Paul A. Madden2 — 1GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam — 2Chemistry Department, University of Edinburgh, Edinburgh EH9 3JJ, UK
The atomic dynamics of Al2O3 melt are studied by molecular dynamics simulation. The particle interactions are described by an advanced ionic interaction model that includes polarization effects and ionic shape deformations. The model has been shown to reproduce accurately the static structure factors S(Q) from neutron and x-ray diffraction and the dynamic structure factor S(Q,ω) from inelastic x-ray scattering. Analysis of the partial dynamic structure factors show inelastic features in the spectra up to momentum transfers, Q, close to the principal peaks of partial static structure factors. The broadening of the Brillouin line widths is discussed in terms of a frequency dependent viscosity η(ω).