Pseudomorphic growth of Pd monolayer on Au(111) electrode surface

The surface structure of a Pd layer electrochemically deposited onto Au(lll ) from PdCl42- solution has been studied by surface X-ray diffraction. By c ombining the measurements of the specular and non-specular rod profiles, bo th in-plane and out-of-plane structures have been determined. On the Au(lll ) electrode surface, Pd occupies the cubic closest packing site and forms a pseudomorphic smooth monolayer. The formation of the stable Pd overlayer i s explained by the lifting of the surface reconstruction of the Au substrat e. The Pd-Au bond length at the Pd/Au(lll) interface has been found to be 2 .82 Angstrom, which is close to the sum of the atomic radii of Pd and Au in each bulk. (C) 2000 Elsevier Science B.V. All rights reserved.