Long & Medium-Term Research: X-ray Analysis of Thin Film Materials Including Wear Resistant Coatings and Superlattice Structure. This award recommendation is made under the Program for Long & Medium-Term Research at Foreign Centers of Excellence. The program seeks to enable U.S. scientists and engineers to conduct long-term research abroad at research institutions of proven excellence. Awards provide opportunities for the conduct of joint research, and the use of unique or compli- mentary facilities, expertise and experimental conditions in foreign countries. This award for a proposal sponsored by Dr. Jerome Cohen is to support a 15 month visit by Dr. Carla J. Shute to Sweden to work with Professor Torsten Ericsson of the Institute of Technology in Link ping on "X-Ray Analysis of Thin Film Materials Including Wear Resistant Coatings and Superlattice Structure." The properties of thin film materials are of considerable interest due to their enhanced mechanical behavior over bulk specimens of the same material. The researchers will examine two types of thin film structures: TiN wear resistant coatings and Mo/V superlattice structures. They will examine the residual stresses in both of these materials by the sin.theta polycrystalline x-ray diffraction technique. For the TiN films, the researchers will study the mechanism of compressive stress generation during growth under low energy ion bombardment. For the Mo/V superlattices, they will examine the tetragonal strain distortion theories for the supermodulus effect. The supermodulus effect is a two-three fold increase in the elastic modulus of thin film modulated structures observed for a small range of wavelengths of the composition modulation. They will also make measure- ments of the tetragonal strain, gradient in strain near the interface, and strength and coherency of the interface as a function of the wavelength of the modulation to determine if coherency strains can explain this enhanced mechanical behavior. The award recommendation provides funds to cover, as appropriate, international travel, local travel abroad, stipend, dependents' allowance if applicable, and a flat administrative allowance of $250 for the U.S. home institution.
