Dynamical anomalies in physisorbed films of Sn(CH3) and Fe(CO)5 on graphite basal plane

Several dynamical properties of Sn(CH₃)₄ and Fe(CO)₅ molecules physisorbed on graphite, are influenced by the form of two-dimensional solid growth. As inferred from Mössbauer results, at temperatures where the molecules form solid superstructures and below monolayer coverages, abnormal changes are observed in the mean squared displacement of the molecules. It is suggested that these dynamical anomalies are associated with substrate-adsorbate registry.