Commensurability transitions in multilayers: A response to substrate-induced elastic stress

Publisher Website
Google Scholar
Abstract
Computer simulations of multilayers adsorbed on graphite show commensurability transitions between the two layers closest to the substrate. At low temperature, the first and second layers are mutually commensurate for films thinner than four layers. As the coverage is slightly increased to four layers, the three top layers form an expanded mutually commensurate slab that is incommensurate to the compressed first layer. As the temperature of the film is increased, the thermal expansion of the system drives the bottom layer into commensurability with the three-layer slab. These transitions appear to be caused by the elastic response of the film to the steep gradient in the substrate-adsorbate potential.