Core-level spectroscopy study of rare-earth metal/W(110) interface formation

The electronic structure of rare-earth metal/W(110) interfaces during the initial stages of deposition has been investigated using core-level shift spectroscopy. Three rare-earth metals (Gd, Y and Yb) have been grown on a W(110) substrate. Shifts in the W 4f(7/2) core level peaks of >300 meV have been confirmed for the clean W(110) surface. On completion of each interface a bulk feature and only one shifted peak is observed which supports evidence that no alloying occurs. At submonolayer coverages an additional feature is seen at higher kinetic energies which is attributed to emission from W atoms under various (n x 2) adsorbate structures.