Ellipsomicroscopy for surface imaging: contrast mechanism, enhancement, and application to CO oxidation on Pt(110)

Ellipsomicroscopy for surface imaging (EMSI) is a powerful new tool for stu dying spatiotemporal adsorbate pattern formation on catalyst surfaces. It i s a surface-sensitive technique that is able to measure submonolayer covera ge of adsorbates. The imaging of the sample's surface achieves a spatial se nsitivity, making it possible to measure nonuniformity of adsorbate coverag e. The image contrast, however, depends strongly on the setup of the instru ment. The optimum setup can be calculated from the ellipsometric properties of the catalyst/adsorbate system and the intrinsic parameters of the EMSI instrument. Optimizing the setup of the EMSI instrument permitted enhanceme nt of the image contrast over the previous setup. Asa result, new features in CO oxidation on Pt(110) were discovered. (C) 2000 Optical Society of Ame rica [S0740-3232(00)01101-7].