Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 21: Amorphous and Liquid Materials II
MM 21.1: Vortrag
Dienstag, 28. März 2006, 16:30–16:45, IFW D
DeGennes slowing down in a liquid metal revisited: A neutron spin echo study — •Franz Demmel1, Peter Fouquet2, Wolfgang Haeussler3, and Christoph Morkel3 — 1ISIS Facility — 2ILL Grenoble — 3TU Muenchen
The decay of density fluctuations shows a slowing down at the structure factor maximum in liquids, which is well known as deGennes narrowing in the frequency domain. Molecular simulations for the liquid metal Rubidium and mode coupling theory has suggested that the relaxation process has to be described with two terms in the memory function [1]. We have probed these predictions by inelastic neutron scattering using the spin echo technique to measure the dynamics directly in the time domain. The liquid alkali metal Rubidium was measured near the melting point with the spin echo instrument IN11C at the ILL, Grenoble. The resulting intermediate scattering function is in remarkable quantitative agreement with predicted values from the mode coupling calculations and the molecular dynamics simulations. The question will be discussed whether this slow decay is related to the solidification process. [1] U. Balucani and R. Vallauri (1989) Phys. Rev. A 40 2796