ABSTRACT
This chapter addresses the preparation of well-ordered thin silica films on metallic substrates. The formation of Si stabilized surface oxide was also observed on the Si-contaminated Pd surfaces, albeit the situation was not so obvious due to the concomitant formation of PdOx layers. The surface unit cells of the Mo(110) and Mo(100) surfaces do not match lattice parameters of silica polymorphs and, therefore, hardly favor the formation of crystalline films requiring good epitaxial relationships at the interface. Based on LEED patterns showing pseudo-hexagonal symmetry of a silica overlayer, several bulk-derived structures of silica polymorphs exhibiting hexagonal layers, like in HP-tridymite and β- cristobalite, were first considered. The silicate layer model received further support from studies using fast hydrogen and helium atom scattering at a grazing incidence.
