Dynamical structure factor for liquid bismuth

Abstract

The scattering function $S\mathrm{}(Q,E)\mathrm{}$ for liquid bismuth at 305°C has been determined by neutron inelastic scattering in the wave-vector transfer range $1.6<Q<\mathrm{}7.2\mathrm{}$ ${\mathrm{\AA }}^{-1\mathrm{}}$ and for energy transfers $E$ up to about 20 meV. The measured $S\mathrm{}(Q,E)\mathrm{}$ satisfies the zeroth- and the second-moment relations within some few percent. The shoulder in the static structure factor $S\mathrm{}\left(Q\right)\mathrm{}$ gives rise to clearly visible effects also in the dynamical-scattering function. The full width at half maximum of $S\mathrm{}(Q,E)\mathrm{}$ exhibits an oscillation at a $Q$ value corresponding to the position of the shoulder. This fact together with some particular features in the same $Q$ range regarding the experimentally obtained spectrum of the longitudinal current-current correlation function indicates that the nature of the molecular dynamics in liquid bismuth is different as compared with simple liquid metals.