Surface electronic structure of Ti-covered W(1 1 1) by photofield emission

Photofield emission (PFE) measurements are employed to examine modifications of the surface electronic structure of the tungsten (1 1 1) facet upon deposition of thin films (1-3 monolayers) of titanium. With the help of DFT simulations, the observed PFE features are interpreted as adsorbate-induced resonance states with energies just below the Fermi level, localized predominantly at the exposed surface atoms. Comparison between the computed surface DOS distributions and the measured PFE spectra is also used to verify various possible arrangements of the Ti adatoms, supporting the DFT-favored model of Ti growth in registry with the W(1 1 1) substrate until a full physical overlayer of the adsorbate is completed. -- Research highlights: →Surface DOS modifications of Ti/W(1 1 1) revealed by photofield emission. →Strong adsorbate-induced resonance states observed at Ti/W(1 1 1) near Fermi level. →Ti growth in registry with W(1 1 1) substrate confirmed up to full physical overlayer.