title: Rainbow scattering of CO and N2 from LiF(001).
abstract: The angular intensity distributions of CO and N(2) molecules scattered from a LiF(001) surface have been measured as functions of surface temperature, incident translational energy, and incident azimuthal direction affecting surface corrugation at a high resolution. Although both molecules have the same molecular mass and linear structure, only the CO molecule shows a rainbow feature in its scattering pattern, while the N(2) molecule shows a single peak distribution. From the comparisons of the obtained results with the calculated predictions based on the newly developed classical theory of the ellipsoid-washboard model, the differences in scattering distribution are attributed to the effects of molecular anisotropy and center-of-mass position. With an increase in the extent of the molecular anisotropy such as that of N(2) and CO as compared with rare-gas atoms, the summation of several scattering distributions depending on molecular orientation results in smearing the rainbow scattering on the corrugated surface. This smearing effect, however, attenuates when center-of-mass position deviates from the molecular center, as that for CO.
authors.affiliation: Surface Chemistry Laboratory, Institute of Chemical and Physical Research (RIKEN), Wako, Saitama, Japan. takahiro@riken.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kondo
authors.forename: Hiroyuki S
authors.initials: HS
authors.lastname: Kato
authors.forename: Taro
authors.initials: T
authors.lastname: Yamada
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Maki
authors.initials: M
authors.lastname: Kawai