https://doi.org/10.1051/epjconf/201715102002
Experimental evidence for two different dynamical regimes in liquid rubidium
1 ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
2 Physikdepartment E21, TU München, 85748 Garching, Germany
* e-mail: franz.demmel@stfc.ac.uk
** e-mail: christoph.morkel@frm2.tum.de
Published online: 21 August 2017
We present evidence for changes in the dynamics of liquid rubidium with rising temperature. The thermal expansion of this liquid alkali metal shows a changing derivative with temperature in a temperature range of about 400-500 K. With neutron scattering the amplitude at the structure factor maximum demonstrates a changing slope with increasing temperature. A derived averaged structural relaxation time can be understood that an additional relaxation process sets in upon cooling. The deduced generalized viscosity and high frequency shear modulus indicate a change in dynamics in the same temperature range. All these findings point to a change in dynamics of the equilibrium liquid metal state with a dynamical crossover from a viscous to a fluid-like liquid metal well above the melting point.
© The Authors, published by EDP Sciences, 2017
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