Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 16: Diffusion and Point Defects I
MM 16.2: Vortrag
Dienstag, 24. März 2009, 11:45–12:00, IFW B
Atom Jumps Studied by Coherent Synchrotron Radiation — •Gero Vogl1, Michael Leitner1, Bastian Pfau2, Bogdan Sepiol1, and Lorenz-Mathias Stadler1 — 1Fakultät für Physik der Universität Wien, Austria — 2BESSY, Berlin, Germany
Measuring the atomic diffusion jump is a fundamental problem in solid state physics. Up to now only measurements involving a limited number of isotopes and in a very limited temperature range were feasible due to the limitations of methods such as quasi-elastic neutron scattering, quasi-elastic Mössbauer spectroscopy or nuclear magnetic resonance.
X-ray photon correlation spectroscopy has the potential to overcome these constraints. We present the first successful implementation of this new technique. We deduce the atomic jump model from the q-dependent relaxation times of diffuse scattering measured at the ESRF and give the activation energy of Au diffusion in CuAu. We predict that the new sources with increased brilliance and high coherence like PETRA or the XFEL will enable determination of the atomic diffusion jump in condensed matter over a wide range.