A modified sudden approximation is introduced for the calculation of elastic atom scattering intensities from surfaces. On the basis of a comparison with the limit of hard wall interaction potentials, this new sudden approximation will have an extended range of validity for scattering into final states with larger parallel momentum exchange. As for any coordinate representation sudden approximation, the method is equally applicable to both periodic and non-periodic surfaces. This paper reports the preliminary results of an investigation of the atom-surface interaction potentials at step edge defects using the new approximation. Comparisons with experimental data of diffuse scattering of He atoms from monatomic steps, on an otherwise perfect Pt(111) crystalline surface, indicate the presence of an attractive well in the vicinity of the step.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry