The adsorption of CO on W(100) at 80 K has been studied by photoelectron spectroscopy at hv=21.22 eV, and the results have been correlated with previous data for room temperature adsorption. Initial adsorption produces a peak in the emission spectrum at ~-7.6 eV (relative to the Fermi energy), which is characteristic of the virgin state of adsorbed CO, as well as additional structures which have been previously shown to be characteristic of α- and β-CO. Upon heating the sample to 260 K the -7.6-eV level is depleted and apparent conversion to the β state occurs as indicated by an enhancement of the emission near -5.5 eV. Additional data taken with hv=16.85, 26.9, and 40.81 eV are in general agreement with the measurements at 21.22 eV; however, the peak at -7.6 eV for hv=21.22 eV is shifted to lower kinetic energies by several tenths of an electron volt at the other photon energies.
Citation: Journal of Vacuum Science and Technology
Pub Type: Journals