Spectromicroscopy of ultrathin Pd films on W(110): interplay of morphology and electronic structure

We have studied the growth of Pd thin films on W(1 1 0), by means of low-energy electron microscopy (LEEM), X-ray photoelectron microscopy (XPEEM), and microspot low-energy electron diffraction (muLEED). Real-time LEEM measurements of the evolution of the film morphology as a function of deposition time showed substantial differences in the growth mechanism at 380 and 1000 K. Imaging the valence band structure with spatial resolution of 60 nm revealed clear differences for the interfacial monolayer film and the 3D islands growing on top at 1000 K. The observed spatial variations in the electronic structure are attributed to bonding, structural and electron confinement effects.