Experimental and ab initio study of the structural and electronic properties of subnanometer thick Ag films on Pd(111)

We present a combined, experimental, and computational investigation of the growth mode and the valence-band structure of Ag/Pd(111) , with the focus on the Ag 4d derived quantum well states. Low-energy electron diffraction and scanning-tunneling microscopy are used to determine epitaxial, layer-by-layer growth of silver on the palladium substrate. High-resolution (in both energy and angle) photoelectron spectra and ab initio density-functional band-structure calculations are compared for 1 and 2 ML silver films along the Γ¯- Mmacr ^' high symmetry line of the surface Brillouin zone. The observed d -derived electronic states and their dispersion are explained in terms of quantum well states. The interaction of the silver 4d electronic states with the palladium substrate is discussed.