Studies of Weakly Adsorbed Layers

This project is a collaborative study employing both experimental and theoretical methods to study fundamental questions about forces at surfaces and their implications for the structure and dynamics of thin films. Key problems to be addressed include when and why many adsorption systems exhibit low-coordination adsorption sites, and whether the existing theory adequately describes the ultra-weak adsorption of simple gases. These studies will extend the groups' previous research, which has established a partial empirical and theoretical base for understanding weak adsorption phenomena. The techniques to be employed are low-energy electron diffraction, He-atom scattering, computer simulations and state-of-the-art theoretical methods. The importance of these studies is that they will provide a fundamental understanding of adsorption phenomena that will be applicable to many different fields, including nano-patterning, self-assembled monolayers, coatings technology, tribology and chip fabrication. Students and postdoctoral scholars will be trained in fundamental methods, which are applicable to the aforementioned technologies.

Surface science is of importance as a subject of both fundamental interest and potential application to many technologies. This project addresses a number of basic scientific questions in this area. Principal problems that will be explored include the structure of films that are just one molecule thick. A focus of this research is the determination of where individual molecules sit in relation to the underlying supporting surface. A second major topic is the question of how strongly these films are bound to the surface as well as their dynamics. In some cases, such films are bound to the surface at high temperature, but not at low temperature. In other cases, the reverse situation is observed to be the case. These phenomena, and many others, will be explored with diverse experimental, theoretical and computational methods. The principal experimental techniques are electron and atom beam scattering from surfaces. Theory and simulation are to be carried out, using state-of-the-art modeling methods, some of which will be further improved as part of the research. The research will benefit from the combination of techniques being applied. Students will be trained in fundamental methods which are applicable to industrial concerns such as the development and fabrication of coatings, lubricants, and computer chips.