Ultrathin Au films on W(110): Epitaxial growth and electronic structure

Gold films between 1 and 11 monolayers in thickness were prepared on W(110) by molecular-beam epitaxy at substrate temperatures between 180 and 550 K. Thickness and quality of the growing films were characterized with reflection high-energy electron diffraction, Auger-electron spectroscopy, and, in particular, with HeI excited angle-resolved ultraviolet photoelectron spectroscopy, which was also used for the study of the electronic structure of the films. The initial quasimonolayer by monolayer growth mode leads to pronounced thickness-dependent changes of the Au electronic states. Quantum-well states derived from the ${\mathrm{\Lambda }}_6$ band of Au are observed for thicker films before the spectra become identical to those well known from bulk Au(111).