title: Zero-point vibration of hydrogen adsorbed on Si and Pt surfaces.
abstract: Hydrogen atoms adsorbed on Si(111) and Pt(111) were investigated by nuclear reaction analysis (NRA) using 1H(15N,alphagamma)12C. From measurements of the NRA spectrum at normal and tilted ion incidences the zero-point vibrational energies of H on Si(111) in the perpendicular and parallel directions were found to be 123.4+/-4.6 and 44.6+/-6.2 meV, respectively, which are consistent with harmonic potentials. The zero-point energies obtained for Pt(111)-H were 80.8+/-3.9 and 62.1+/-6.0 meV for perpendicular and parallel directions, respectively. These results indicate that the stretching mode is harmonic, while the bending mode is strongly anharmonic.
authors.affiliation: Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan. fukutani@iis.u-tokyo.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Fukutani
authors.forename: A
authors.initials: A
authors.lastname: Itoh
authors.forename: M
authors.initials: M
authors.lastname: Wilde
authors.forename: M
authors.initials: M
authors.lastname: Matsumoto