Structure determination by angle scanned x-ray photoelectron diffraction

Abstract EN

The various wavs in which surface structural information can be obtained by measuring angle-scanned X-ray photoelectron diffraction from single-crystal surfaces are reviewed.

By means of a few selected recent experiments we discuss applications to different classes of problems in surface Science, such as the bonding geometry of molecular adsorbates, relative adsorbate-substrate atom positions, the growth of ultrathin pseudomorphic overlayers, interdiffusion, surface recon- struction, and also thermal and magnetic properties of clean surfaces.

In many cases strong forward-scattering-related intensity maxima reveal the orientation of principal bond axes.

The comparison of intensity modulations in polar and azimuthal scans along lower-symmetry directions with scattering-cluster calcula- tions permits the determination of bond lengths.

The particular dass of surface system involved, as well as symmetry arguments, are decisive elements in the proper choice of scanning directions, and of the specific photoemission signal to be monitored.