Atomic geometry of the PbS(100) surface

• Published in: Surface science 1998-01, Vol.395 (2-3), p.229-238
• Main Authors: Kendelewicz, T., Liu, P., Brown, G.E., Nelson, E.J.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Photoelectron spectroscopy; Physics; Solid surfaces and solid-solid interfaces; Surface relaxation; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); X-ray standing waves
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(97)00627-4

The surface structure of PbS(100), in the form of the mineral galena, was studied with the X-ray standing wave technique using surface-sensitive Auger electron yield detection and normal incidence geometry. We find that neither S nor Pb surface atoms are displaced from their respective bulk site positions. This lack of surface relaxation differs from the recent suggestion based on theory that a sizable contraction is needed to explain the experimentally observed lack of a surface core-level shift in Pb 5d photoemission data. To shed more light on this issue, we have also measured high-resolution Pb 4f, Pb 5d, and S 2p photoemission spectra for PbS(100) and confirmed that the surface core-level shifts are absent for cations as well as for anions.