LAYER-BY-LAYER MELTING OF ARGON FILMS ON GRAPHITE - A NEUTRON-DIFFRACTION STUDY

Elastic neutron diffraction is used to study the melting of multilayer argon films physisorbed on a graphite substrate. The layers are found to disorder sequentially from the outermost layer of the film toward the graphite surface with the melting of individual layers occurring gradually over a temperature range of about 10°. For films initially two or more layers thick the melting of the layer closest to the substrate occurs near 100 K. Comparisons are made with recent computer simulations and with thermodynamic measurements. © 1990 The American Physical Society.