Abstract
Photoemission spectra are reported for Au on W(110) which show series of pronounced peaks up to large film thicknesses [about 15 monolayer (ML)] which are assigned to quantum-well states of Au sp and Au d character. Due to its large bandwidth and low binding energy, sp and d states are largely degenerate in Au. Therefore, Au overlayers serve as an interesting test system for simple models of quantum-well-state formation. A good description of all of the observed features is reached based on our extended phase accumulation model analysis. Assignment to several branches of sp- and d-type quantum-well states is reached based on (i) our model treatment, (ii) the asymptotic behavior for large thicknesses, (iii) an analysis of the angle dispersion, and (iv) a comparison between the system without and with an extra Ag interlayer. For the latter it is found that sp-type quantum-well states form throughout the combined layer already from lowest coverages on, whereas formation of d-type quantum-well states is largely suppressed. Using our model treatment we reach a thorough description of both systems for the whole thickness range starting out from submonolayer coverages and correct previous assignments in the literature. In addition, the role of hybridization in the overlayer is discussed.
- Received 19 July 2001
DOI:https://doi.org/10.1103/PhysRevB.65.075403
©2002 American Physical Society