A theory of He diffraction and resonance scattering from Cu(115) by the complex coordinate method

Abstract

Cumulative reaction probability by the complex coordinate scattering theory J. Chem. Phys. 98, 6327 (1993); 10.1063/1.464826The complex coordinate scattering theory and the Kohn variational method: A general formulation and application to long range potentials J. Chem. Phys. 97, 6443 (1992); 10.1063/1.463702The complex coordinate scattering theory: Broken inversion symmetry of corrugated surfaces in helium diffraction from Cu (115)

Extreme sensitivity of corrugation strength on diffraction resonance line-shapes for the gas-surface system He (21 meV)/Cu (115)

“…In previous works [ 1,2], a good agreement between calculations and experiments over the whole incident angular range for the gas-surface diffraction system, He( 2 1 meV)/Cu( 115), was obtained. The agreement concerned both the off-resonance elastic relative intensities in between the selective adsorptive resonances and the line-shape signatures of the narrow resonance structures.…”

“…In Ref. 2, it was found that the choice h = 0.027 lead to reproduction of experimental specular as well as nonspecular intensities. In this work, this parameter is varied and the line-shape of the selective adsorptive resonance labeled ( ho) is studied.…”

“…= P o COS ? (') = (pi -( p p ' ) 2 ) 1 / 2 ( 2 ) where v runs over those integers such that p p ) is real. v = 0 Gives the specularly diffracted beam with y (O) = y .…”

The complex coordinate scattering theroy and its application to the study of the surface asymmetry effect in helium diffraction from copper

“…When the de Broglie wave length of the incoming He atom is in the scale of the corrugation dimensions (i.e., in the low-energy range of 10'-102 meV), the diffraction intensities serve as a major tool for obtaining detailed information about the surface structure and the physisorption interaction potential between the gas atom and the solid surface [l]. Recently, Engdahl et al [2,3] calculated the diffraction intensities for the scattering of atomic He beam from the surface of Cu(ll0) and Cu(115) using the Complex Coordinate Scattering Theory. A fairly good agreement between their theoretical results and the experimental ones obtained by Perreau and Lapujoulade [4] was achieved when the surface corrugation function contained only one dimensionless fitting parameter, i.e., the corrugation strength parameter, h.…”

“…The calculations described in [2] assumed a symmetric corrugation for both the (110) and the (115) faces of the Cu crystal. The agreement that was achieved between the theoretical and the experimental intensities (especially when the incident angles between the molecular beam and the surface normal were large) led to a conclusion that the surface asymmetry effect on the diffraction pattern is minor and can be neglected.…”