title: Spreading and two-dimensional mobility of long-chain alkanes at solid/gas interfaces.
abstract: Long-chain n alkanes on solid surfaces can form partially wetting liquid alkane droplets coexisting with solid multilayer terraces. We propose a diffusivelike alkane flow between terrace edge and droplet perimeter through a molecularly thin "precursorlike" film. Depending on the (uniform!) sample temperature, either droplet or terrace edge are not in thermodynamic equilibrium. This leads to a chemical potential gradient, which drives the reversible alkane flow. The gradient can be adjusted and calculated independently from the phenomenological diffusion coefficient.
authors.affiliation: Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Am Mühlenberg, D-14476 Potsdam, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Lazar
authors.forename: H
authors.initials: H
authors.lastname: Schollmeyer
authors.forename: H
authors.initials: H
authors.lastname: Riegler