Dynamics on next-neighbour distances in liquid and undercooled gallium. (15th November 2018)

• Record Type: Journal Article
• Authors: Demmel, F
• Is Part Of: Journal of physics. Volume 30:Number 49(2018)
• Publication Date: 2018-11-15
• Subjects: liquid dynamics -- liquid metals -- neutron scattering; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aaeb72
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Density fluctuations of liquid and 20 K undercooled gallium have been studied by neutron spectroscopy. The decay of density fluctuations has been recorded at the structure factor maximum over a wide temperature range up to twice the melting temperature. The amplitude of the scattering function falls off with rising temperature in a nonlinear way with a changing slope around . The derived generalized longitudinal viscosity shows an upturn with decreasing temperature in the same temperature range. This increase in viscosity can be understood that liquid gallium transforms from a more fluid liquid metal to a more viscous liquid metal in that temperature range upon cooling. The change in the amplitude shows a remarkable agreement with results from liquid aluminium, lead and rubidium. This study suggests a universal crossover in dynamics of liquid monatomic metals, despite the many peculiar properties of gallium.