Electronic properties of Fe clusters on a Au(111) surface

The electronic states of self-organized Fe nanoislands on a Au(111) surface have been investigated using low-temperature scanning tunneling microscopy and spectroscopy. We show that the local density of states is dominated by Shockley surface states confined in the nanostructures. Comparing the experimental dispersion diagram with a free-electron model we derive the effective mass m* = 0.39m(e) and the band onset E-0 = -420 meV of these states. Ab initio calculations show the existence of the Shockley surface states in the Fe layer, in agreement with the experiment, and reveal that they are fully spin polarized