Evidence by angle-scanned photoelectron diffraction for a CO- induced restructuring of a Ni/Pt(111) monolayer

Angle-scanned photoelectron diffraction measurements have been performed prior to and after CO exposure onto a Ni monolayer deposited on Pt(111). Ni is known to grow epitaxially on Pt(111), but there is evidence for an adsorbate-induced restructuring such that the initial atomically flat Ni layer gives place to at least two-layer-high Ni islands. As far as the driving force for the restructuring is concerned, some hypotheses can be put forward considering the Ni–Ni nearest neighbor distances in the Ni monolayer and in the restructured layer, along with some thermodynamical arguments.