Dynamics of glassy and liquid selenium

Inelastic-neutron-scattering studies of glassy, liquid, and polycrystalline selenium have been performed at temperatures between 100 and 600 K. A self-consistent data evaluation, taking careful account of multiple and multiphonon scattering, shows that a complete interpretation is possible in terms of a temperature-dependent density of vibrational states, together with diffusion broadening of the elastic line. This density of states is used to calculate thermodynamic properties and to show that about one-third of the additional entropy of the liquid is vibrational. The results raise a number of questions concerning current theories of the glass transition.