INTERACTION OF CFCL3 WITH AN FE(100) SURFACE .2. ADSORPTION AND DECOMPOSITION AT AMBIENT-TEMPERATURES

Results are presented which are obtained for room temperature adsorption and annealing the adsorbate covered surface up to 800 K. Dissociative adsorption at 300 K proceeds with a high and constant sticking coefficient which is explained by the long lifetime ( greater than 3 multiplied by 10** minus **5 s) of the molecule in the extrinsic precursor state. Chlorine adsorbs on the surface forming a noncoincidence overlayer raft while carbon and fluorine are absorbed in the selvedge. These absorbed atoms have a distinct influence on the surface structure and the stability of the chlorine overlayer. Absorbed fluorine stabilizes the chlorine overlayer up to 700 K, which is a significantly higher temperature than observed for the stability of chlorine overlayers formed by Cl//2 or CCl//4 adsorption.