Reflection anisotropy microscopy: improved set-up and applications to CO oxidation on platinum

Reflection anisotropy microscopy (RAM) is a novel technique to spatially resolve the optical anisotropy of surfaces. We describe a substantially improved set-up, utilizing a Foster prism. As a result the image contrast was significantly enhanced and the light source now can be polychromatic. We also present applications to CO oxidation on platinum. For CO adsorption on Pt(110), the RAM signal was correlated to the surface structure. For CO oxidation on Pt(110) under the conditions of pattern formation, the surface reconstruction was spatially resolved. For a polycrystalline platinum foil individual crystal grains were imaged and their crystallographic structure was identified.