Hydrogen diffraction from the (110) surface of silver

Abstract

The scattering of H₂ and D₂ molecules at thermal energies from the Ag(110) surface has been studied by means of nozzle-beam techniques. Diffraction peaks of comparable intensities are present along both the [001] and the [110] azimuthal directions, indicating a two-dimensional repulsive corrugation. The diffraction intensities were resolved over a wide range of incident angles and energies. The experimental H₂ data are analysed theoretically to obtain information on the repulsive molecule–surface interaction potential. The calculations are performed (a) with the hard-corrugated-wall potential, (b) with a soft-corrugated-wall model and (c) performing close-coupling calculations for a flexible phenomenological potential. The best-fit interaction potential shows that the two-dimensional repulsive corrugation has a weak dependence on energy. A comparison is made between the H₂–Ag(110) and He–Ag(110) potentials and the H₂ and He diffraction from the Ag(111) and Cu(110) surfaces.