Regensburg 2004 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 26: General Statistical Physics
DY 26.1: Vortrag
Dienstag, 9. März 2004, 16:45–17:00, H2
Long-term correlations distinguish coarsening mechanisms in alloys — •Lorenz-M. Stadler1, Bogdan Sepiol1, Richard Weinkamer2, Markus Hartmann2, Peter Fratzl2, Jan W. Kantelhardt3, Federico Zontone4, Gerhard Grübel4, and Gero Vogl1 — 1Institut für Materialphysik, Universität Wien, 1090 Wien, Austria — 2Max-Planck-Institute of Colloids and Interfaces, Department of Biophysics, 14424 Potsdam, Germany — 3Institut für Theoretische Physik III, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany — 4ESRF, BP 220, 38043 Grenoble Cedex, France
We determine long-term correlations in the time series of fluctuating x-ray speckle intensities. A fluctuation analysis of small angle x-ray scattering data of the two phase-separating alloys Al-6at.%Ag and Al-9at.%Zn at late stages of phase separation reveals long-term correlations that are dramatically different for the two systems. From a comparison with recent Monte Carlo simulations we conclude that two different coarsening mechanisms are predominant in the two alloys—coarsening either by diffusion of single atoms or by movement of whole precipitates.
We acknowledge financial support from the Austrian Federal Ministry for Education, Science and Culture (project GZ 45.529/2-VI/B/7a/2002) and the Hahn-Meitner-Institute Berlin in cooperation with the University of Potsdam.