Inelastic x-ray scattering study of liquid Ga: Implications for the short-range order

The high-frequency dynamics of liquid gallium is investigated by inelastic x-ray scattering at high pressure using a crystal-like approach for the data analysis to extract the dispersion curves of the quasitransverse and quasilongitudinal acoustic excitations. A strict relation between these dispersion curves and those of solid monoclinic β-Ga is found, confirming the similarity between these two phases already suggested by structural investigations. This result shows that the high-frequency dynamics of liquids holds, similarly to crystals, rich and system-specific information, and establishes a clear connection between microscopic structure and dynamics.