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M: Metallphysik
M 3: Flüssige und amorphe Metalle II
M 3.3: Vortrag
Freitag, 4. März 2005, 12:00–12:15, TU H111
The temperature dependence of the deGennes narrowing in liquid Rubidium — •Franz Demmel1 and Christoph Morkel2 — 1ILL, Grenoble — 2TU München, München
Recent diffraction experiments on levitated undercooled liquid metals have been modelled with a contribution of icosahedral clusters in the melt. The temperature dependence of the density time correlation function at next neighbour distances should also be a sensitive parameter for detecting clusters and their possible melting. We performed coherent inelastic neutron scattering experiments on the alkali metal Rubidium around the structure factor maximum. Fifteen temperatures from the melting point up to two times the melting point have been measured. The experiment was performed at three axis spectrometers of the Forschungsreaktor München FRM and at the ILL, Grenoble. The line width shows a linear increase with temperature. But the peak values decrease in a nonlinear way and indicate a change in dynamics around 1.5*Tmelt. One can speculate whether this decrease in amplitude above the macroscopic melting temperature is related to the melting of solid-like structures (clusters) in the liquid state.