Electron beam induced desorption and dissociation of CO chemisorbed on Ir(111)

Election beam induced perturbations of CO chemisorbed on Ir(111) have been measured using LEED and AES. The total interaction cross-section for electron-stimulated desorption and dissociation is found to be 0.8 to 1.7 × 10^?17 cm² near $\text{1}\text{3}$monolayer coverage at a beam energy of 86 eV. This total cross-section is estimated to be 1 × 10^?17 cm² when defined with respect to the primary flux of a 2.5 keV beam. Electron-stimulated dissociation is found to occur at 1–2% of the rate of stimulated desorption.