Surface state of Gd(0001) films on W(110): Scanning tunneling spectroscopy study

The surface electronic structure of Gd(0001)/W(110) has been studied by scanning tunneling spectroscopy in dependence of the coverage. An exchange split d(z2)-like surface state which is well known from photoemission experiments was already found for coverages as low as 2 ML. The exchange splitting was found to increase with increasing coverage up to the fourth ML. For higher coverages the electronic structure remains constant. We found spectra that are shifted by approximate to 25 meV, possibly due to stacking faults.