title: Questions arising for future surface diffusion studies using scattering techniques--the case of benzene diffusion on graphite basal plane surfaces.
abstract: This paper gives a review of recent work on benzene diffusion on graphitic carbon surfaces using neutron and helium scattering spectroscopy as well as computational modelling. Recent spin-echo spectroscopy measurements have demonstrated that benzene/graphite displays almost perfect Brownian diffusion and that it can be used as a tool to study dynamic friction. Incoherent neutron backscattering measurements, on the other hand, reveal a jump diffusion behaviour, related to the molecular rotational modes of the benzene rings. Molecular dynamics (MD) simulations have delivered a very detailed picture of the adsorbate dynamics. We use this review to illustrate the open questions and possible future directions of this research field.
authors.affiliation: Institut Laue Langevin, Grenoble, France.
authors.forename: Irene
authors.initials: I
authors.lastname: Calvo-Almazán
authors.forename: Tilo
authors.initials: T
authors.lastname: Seydel
authors.forename: Peter
authors.initials: P
authors.lastname: Fouquet