Microscopic motions in molten potassium spanning three frequency decades are studied by neutronscattering techniques. These comprise well-defined density oscillations and stochastic particle rearrangements and both are modeled on microscopic grounds. While vibratory motions are shown to share characteristics with those of their parent crystals, dynamic correlations between a diffusing particle and its neighbors can be accounted for only semiquantitatively.

No abstract

The advent of inelastic x-ray scattering techniques has prompted a reawakened interest in the dynamics of simple liquids. Such studies are often carried out using simplified models to account for the stochastic dynamics that give rise to quasielastic scattering. The vibrational and diffusive dynamics of molten potassium are studied here by an experiment using neutron scattering and are shown to provide some clues to understand the basic thermodynamics of the liquid state. The findings reported here suggest ways in which the true complementarity of neutron and x-ray scattering may be profitably exploited.