Atomic dynamics of liquid Hg studied by high-resolution inelastic x-ray scattering

High-resolution Inelastic X-ray Scattering (IXS) is a powerful tool for measuring the dynamic structure factor, S(Q,ω), in liquids. Very recently, we began to operate a new instrument that allows practical measurements on liquids of the most interesting low Q region at BL43LXU of the RIKEN SPring-8 Center in Japan. Liquid dynamics in this region is important since this region corresponds to transition from hydrodynamic to solid-like elastic regimes. Liquid metals are particularly interesting since they behave quite differently from molecular liquids due to strong atomic interactions. We use the new setup to investigate liquid Hg with energy resolution >0.8 meV at temperature near the melting point T_m = 234.3 K. We will discuss details of transition of the speed of sound in liquid Hg, the quasi-elastic line-width, and a new approach to fitting dynamical spectra.