| The structure and dynamics of surfaces and thin films are currently the subject of much research due to their applicability to the modern electronic and materials industries. I have studied three systems in the surface and thin films topic areas: the surface and dynamics of oxygen-covered Cu(100), the surface morphology of polyimide films, and molecular alignment within cellulose ester films. The principle experimental techniques utilized were low-energy electron microscopy (LEEM), atomic force microscopy (AFM), and infrared spectroscopy in both reflection and transmission modes.; On Cu(100), I studied one well-known and three novel surface phases involving oxygen, including phase change dynamics. Using LEEM, a relatively new and powerful tool for surface microscopy, I found these novel phases by exploring temperatures not previously studied in the literature for the oxygen on Cu(100) system. I also analyzed the motion of single atomic steps on a surface exhibiting one well-known oxygen on Cu(100) structure, which yielded information on the diffusion kinetics of that surface. I describe the LEEM instrument and explain how it works. I also give an overview of the facility at UC Davis that houses this instrument, together with other useful surface analysis tools.; I also investigated the effects of rubbing thin polyimide film surfaces with cloth, a common procedure used in industry in the creation of liquid crystal displays. Using an AFM, I was able to study, at both the micrometer and nanometer scale, tears in the film and the alignment of nanometer-scale islands produced by rubbing. I examined the effect of varying thickness, as well as preparation conditions, on these features.; Using infrared reflection-absorption spectroscopy, as well as infrared transmission spectroscopy, I was able to probe the molecular alignment within films of three cellulose esters. Since the modes of the cellulose molecule were not well-identified in the literature, I began this investigation by matching modes with the specific molecular vibrations which produce those resonances. I then used this information to discern the alignment of these molecules in the film, and the affect on that alignment of annealing. |
