Diffraction studies on ethylene and ethylene-xenon films adsorbed on graphite

• Published in: Physica B + C 1986, Vol.136 (1), p.7-11
• Main Authors: Satija, Sushil K., Passell, L., Wicksted, J.
• Format: Article
• Language: English
• ISSN: 0378-4363
• DOI: 10.1016/S0378-4363(86)80008-0

Results of neutron diffraction studies on monolayer and multilayer ethylene adsorbed on graphite are reported. In the monolayer regime, ethylene shows two incommensurate solid phases. At higher coverages and at low temperatures a coexistence of one adsorbed layer and bulk phase is observed. Increasing the temperature gives rise to distinct layering transitions involving the transfer of molecules from the bulk to the adsorbed phase, ultimately resulting in a surface wetting transition near the triple point of ethylene. Preplating of graphite with one layer of xenon prevents even a single ethylene layer to be adsorbed at low temperatures. The layering and the ultimate wetting transition, however, seem to be unaffected by the preplated xenon layer.