HIGH-FREQUENCY DYNAMICS IN A MOLTEN BINARY ALLOY

Heavily damped excitations are found in molten Li4Pb by inelastic neut ron scattering. The experiment covered a kinematic range which enabled an unambiguous characterization of such excitations by means of the s tudy of the wave vector dependence of their frequencies, lifetimes, an d signal amplitudes. It is shown that the excitations being sampled ex hibit features which substantially deviate from those expected for the propagation of an acoustic mode (which should involve in-phase atomic displacements).