| AVS 54th International Symposium | |
| Surface Science | Tuesday Sessions |
| Session SS1-TuA |
| Session: | Bimetallics and Alloys |
| Presenter: | W. Kim, Korea Research Institute of Standards and Science |
| Authors: | W. Kim, Korea Research Institute of Standards and Science S. Han, Korea Research Institute of Standards and Science D. Lee, Korea Research Institute of Standards and Science C. Hwang, Korea Research Institute of Standards and Science C. Min, Seoul National University, Republic of Korea H. Lee, Pohang Accelarator Laboratory, Republic of Korea H. Kim, Pohang Accelarator Laboratory, Republic of Korea |
| Correspondent: | Click to Email |
Formation of quantum well states in the metallic thin film systems satisfying specific boundary conditions leads to the oscillation of the electron density of states at Fermi level as the thickness of the film increases.1 We investigated the effect of the oscillation on adsorption of CO molecules in case of the Cu/Co/Cu(100) system. The quantum well states and resulting oscillation of density of states at Fermi level in wedge-shaped Cu/Co/Cu(100) system were confirmed by angle-resolved photoemission spectroscopy. After adsorption of CO molecules at the substrate temperature of 100 K, we observed the shift of binding energies of quantum well states, which could be understood in the scheme of phase accumulation model. C 1s core level photoemission spectra of the adsorbed molecules were measured as a function of temperature for each Cu thickness. The initial feature of the C 1s spectra show well-known three peak structure similar to that of CO molecules adsorbed on Cu(100). From the temperature dependence of the intensity of measured C 1s core level spectra, we could determine the desorption temperature of CO molecules for each Cu thickness, which showed clear dependence on the density of states of Fermi level with oscillating variation of 15 K. We also evaluated the relative ratio of the first satellite peak to main peak in C 1s core level spectra and found out that the ratio showed oscillatory behavior and strong correlation with the density of states at Fermi level. Our observations confirm the old theoretical explanation on the origin of three peak structure of C 1s core level spectra of CO molecules adsorbed on the Cu(100) surface.2
1 Z. Q. Qiu and N. V. Smith, J. Phys.: Condens. Matter vol.14, R169.
2 O. Gunnarsson, and K. Schöhammer, Phys. Rev. Lett. vol 41, 1608.