Angle-Resolved Photoemission Study of CO/Co (0001).
Abstract
In this study the techniques of LEED and angle- and energy-resolved photoemission have been used to investigate some of the properties of CO/Co(0001). The orientation of the CO molecules was determined using well-established symmetry selection rules. The CO-CO direct interaction was measured by mapping out the E vs. k4 dispersion of the 4 sigma and combined 5 sigma/1 pi levels of CO in several directions in the Surface Brillouin Zone (SBZ) at two coverages of CO, corresponding to the saturated room and low (170 deg K) temperature phases. The dispersion can be related to the size and shape of the SBZ and correspondingly to the geometry of the CO overlayer in real shape. After preliminary LEED work, a photoemission study was performed at the Synchrotron Radiation Lab of the University of Wisconsin. Two distinct peaks were seen in the UPS spectra of CO/Co(0001) with p-polarization of the incident light, as is generally observed on other transition metals. The consensus is that the level with the higher binding energy (at approx. 11 eV) corresponds to the 4 sigma level of the isolated CO molecule, while the level at approx. 8 eV is a superposition of the molecular 5 sigma and l pi levels, with the 5 sigma level having undergone a bonding shift of approx. 3 eV with respect to the free molecule. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 04, 1981
- Accession Number
- ADA107575
Entities
People
- D. Heskett
- E. W. Plummer
- F. Greuter
- H.-j. Freund
Organizations
- University of Pennsylvania