Structural and electronic properties of the Ti/W(1 1 1) adsorption system

• Published in: Surface science 2009-08, Vol.603 (16), p.2507-2519
• Main Authors: Ha¸dzel, P., Jurczyszyn, L., Kucharczyk, R.
• Format: Article
• Language: English
• Subjects: Adsorption; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density functional calculations; Exact sciences and technology; Photofield emission; Physics; Surface relaxation and reconstruction; Titanium; Tungsten
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2009.06.002

We present theoretical and experimental study of the structural and electronic properties of the Ti/W(1 1 1) adsorption system. Atomic arrangements of the considered surfaces and their electronic structures have been obtained from first-principles pseudopotential calculations based on the density functional theory in a plane-wave-basis implementation. The corresponding experimental data have been provided by photofield emission spectroscopy. Investigations of the clean and Ti-covered W(1 1 1) surfaces indicate substantial structural relaxations deep into the substrate, and a noticeable modification of the surface electronic properties of the system induced already by a thin film of titanium. Configuration with adatoms positioned in substrate-lattice-continuation (i.e., deep-hollow) sites is found to be energetically most favorable. A good agreement between the measured photofield emission spectra and the computed local-density-of-states distributions confirms our theoretical predictions for a clean W(1 1 1) substrate as well as Ti coverages of 0.25 and 1 ML.