Effects of vibrational and rotational excitations on the dissociative adsorption of O on Cu surfaces

Moritani, Kosuke*; Tsuda, Muneyuki*; Teraoka, Yuden; Okada, Michio*; Yoshigoe, Akitaka ; Fukuyama, Tetsuya*; Kasai, Toshio*; Kasai, Hideaki*

We report an X-ray photoemission study of the dissociative adsorption of O at Cu(111), (001), and (110) surfaces with an O molecular beam generated with a variable temperature nozzle. The O-uptake curves, which are produced from precisely measured O-1s peaks, indicate that the dissociative absorption is enhanced as the nozzle temperature is increased up to 1000 K for the normal incidence of O at a kinetic energy of 0.5 eV. However, further increasing the nozzle temperature to 1400 K reduces the probability of dissociativeadsorption. These results suggest that vibrational excitations of incident O assist dissociative adsorption while rotational excitations hinder it.