Structural Chemisorption of CO onto Si(ll1) 7 x 7.

Based on SEXAFS results for 0.5, 1 and 2 ML (monolayers) of CO deposited onto Si(ll1) 7 x 7 at room temperature, we obtain the structure of the chemisorption in this model system. The 7 x 7 order of the substrate determines the chemisorption geometry and coordination numbers for the first 0.7ML of Co. At 2ML a CO-rich overlayer covers the interface.