title: High-frequency subsurface and bulk dynamics of liquid indium.
abstract: We have performed bulk and surface-sensitive inelastic x-ray scattering experiments on liquid indium with 3 meV energy resolution. The experimental data are well reproduced within a generalized hydrodynamic model including structural and microscopic relaxation processes. We find a longitudinal viscosity of 22 mPa s in the near-surface region compared to 7.4 mPa s in the bulk. The origin of the increase is associated with a slowing down of the collective dynamics in a subsurface region of 4.6 nm.
authors.affiliation: Max Planck Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Reichert
authors.forename: F
authors.initials: F
authors.lastname: Bencivenga
authors.forename: B
authors.initials: B
authors.lastname: Wehinger
authors.forename: M
authors.initials: M
authors.lastname: Krisch
authors.forename: F
authors.initials: F
authors.lastname: Sette
authors.forename: H
authors.initials: H
authors.lastname: Dosch