Atomic structures and compositions of interfaces. Progress report, September 1, 1989--August 31, 1990

This research program focuses on an experimental study of the structure and chemistry of metal/metal oxide internal interfaces; the latter are mainly created, although not exclusively, by internal oxidation of binary or ternary metal alloys that are solid-solution phases prior to the internal oxidation treatment. The principal research tools are transmission electron microscopy (TEM), high resolution microscopy (HREM), analytical electron microscopy (AEM) and atom-probe field-ion microscopy (APFIM). The APFIM technique is used to determine the chemical composition of the interfacial region on an atomic scale. Initial studies are foucused on Pd/NiO, Cu/MgO, Cu/Al{sub 2}O{sub 3}, Cu/SiO{sub 2} interfaces, as well as metal oxides in Pt-based alloys. Topics of importance include coherency effects, misfit dislocations, structure of the terminating layer between the metal and the metal oxide, microstoichiometry, dipole space charge effects, and distributions of impurities and point defects at the interfacial region