X-ray Compton Scattering Study of Liquid Germanium and Tin

X-ray Compton scattering measurements have been carried out on germanium (Ge) and tin (Sn) in the solid and liquid states. While the shape of the Compton profiles (CPs) of Ge reflects the semiconductor-to-metal transition upon melting, it was found that even for Sn, which remains metallic during the solid-liquid phase transition, the shape of the CP in the liquid state exhibits more metallic characteristics than that in the solid state. The experimentally derived Fermi momenta of liquid Ge and Sn have systematically higher values than those of the electron gas at corresponding electron densities, which indicates a non-simple metallic nature of the group IV elements in the liquid state.