Experimental evidence for a dynamical crossover in liquid aluminium. (14th October 2015)

• Record Type: Journal Article
• Authors: Demmel, F; Fraile, A; Szubrin, D; Pilgrim, W-C; Morkel, C
• Is Part Of: Journal of physics. Volume 27:Number 45(2015)
• Publication Date: 2015-10-14
• Subjects: liquid metals -- dynamics -- neutron scattering; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/45/455102
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The temperature dependence of the dynamic structure factor at next-neighbour distances has been investigated for liquid aluminium. This correlation function is a sensitive parameter for changes in the local environment and its Fourier transform was measured in a coherent inelastic neutron scattering experiment. The zero frequency amplitude decreases in a nonlinear way and indicates a change in dynamics around . From that amplitude a generalized viscosity can be derived which is a measure of local stress correlations on next-neighbour distances. The derived generalized longitudinal viscosity shows a changing slope at the same temperature range. At this temperature the freezing out of degrees of freedom for structural relaxation upon cooling sets in which can be understood as a precursor towards the solid state. That crossover in dynamics of liquid aluminium shows the same signatures as previously observed in liquid rubidium and lead, indicating an universal character.