This award supports Professor Patricia Thiel, Dr. Luke Chang and a graduate student from Iowa State University to collaborate in surface chemistry research with Professor R. J rgen Behm and others of the University of Ulm, Germany. Both groups are actively pursuing research on metal film growth and structure. Together, they have chosen to study the morphology of a particular metal-on- metal system, and the mechanisms by which that morphology is achieved. Specifically, they will use Scanning Tunneling microscopy (STM) to elucidate the morphology of a system composed of Rhodium on Silver (Rh on Ag(100)). These metals are immiscible and do not appear to form an alloy, but when combined they exhibit very unusual behavior by forming a multi-layer sandwich of Ag-Rh-Ag. The two research groups bring complementary expertise to this complex study: the U.S. group contributes expertise in the particular metal system and the German group offers experimental facilities and well-established experience with STM of metals. Films of solid materials are used in applications which range from corrosion-resistant coatings to magnetic recording devices. The characteristic of a film that is most important in determining its physical properties and thus its performance in a given application is its morphology. The research proposed in this collaboration is directed at understanding the factors which control film morphology, particularly in the complicated case where there is a mixture of materials involved which may form an alloy or a sandwich.
