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Dynamik Vortrag: Mi., 11:50–12:10 M-V7
Collective excitations in a molten transition metal
Walter Schirmacher 1,2 , Harald Sinn 2 , Ayman Said 2
1 Phys. Dept. E13, TU München. D-85747 Garching, Germnay – 2 Argonne National
Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439,
We report inelastic X-ray scattering measurements of the atomic collective excitations
of an early transition metal, namely liquid titanium at T=2020 K. The data show well
defined sound excitations with a low damping constant comparable to the damping observed
in liquid alkaline metals. Calculations of the spectrum of density fluctuations as
a function of the excitation wave number based on Götzes self-consistent mode coupling
approach were carried out. The calculations were performed on the knowledge of the
static structure factor and number density of liquid titanium only, no adjustable parameters
were used. A remarkable agreement between the prediction of mode-coupling
theory and experiment is observed.