IRAS STUDY OF ADSORPTION AND TRANSFORMATION OF CH2I2 ON AL(111) SURFACE

Adsorption of CH2I2 on Al(111) surface was studied by Infrared Reflect ion Absorption Spectroscopy (IRAS). Surface hydrocarbon species CHx we re formed in two stages, even at 98 K and above 133 K. Orientations of solid phase of CH2I2 on Al(111) surface were also studied by IRAS. Mo noclinic-like phase I' was found to form with its I-C-I plane inclined and H-C-H plane perpendicular to the Al(111) surface between 93 and 1 73 K. Phase transition of the phase I' to the face-centered-like phase II started between 133 and 173 K. None of the species with both I-C-I and H-C-H planes perpendicular to the Al(111) was observed.