Initial stages of Pd deposition on Au(1 1 0): A STM, LEED and AES study

Thin Pd films deposited on the missing row (MR) reconstructed Au(1 1 0)-(1×2) surface have been studied using scanning tunneling microscopy, low energy electron diffraction and Auger electron spectroscopy. In the first step of Pd deposition, Pd adatoms fill in the MRs of the Au reconstructed surface and are next covered by Au atoms. This Au surface segregation leaves one-dimensional holes on the surface, and a mixed Au–Pd interface is thus formed. With increasing Pd coverage, a Pd layer grows pseudomorphically onto the mixed interface in a two-dimensional mode up to 2–3 ML. Then, beyond 4 ML, 3D anisotropic islands elongated in the [1 1̄ 0] direction are grown. The formation of the alloyed phase, then the 3D island growth both contribute to relax tensile strain between Pd overlayers and Au substrate.