Adsorption of hydrogen on stable and metastable Ir(100) surfaces

Beitrag in einer Fachzeitschrift

Details zur Publikation

Autor(en): Arman MA, Klein A, Ferstl P, Valookaran A, Gustafson J, Schulte K, Lundgren E, Heinz K, Schneider MA, Mittendorfer F, Hammer L, Knudsen J
Zeitschrift: Surface Science
Verlag: Elsevier B.V.
Jahr der Veröffentlichung: 2017
Band: 656
Seitenbereich: 66-76
ISSN: 0039-6028
Sprache: Englisch


Using the combination of high resolution core level spectroscopy and density functional theory we present a detailed spectroscopic study for all clean and hydrogen covered phases of Ir(100). The results are complemented by an investigation of the hydrogen desorption process from various phases using temperature programmed desorption spectroscopy and scanning tunneling microscopy. In total, all experimentally determined core level shifts match very well with those predicted by density functional theory based on established structural models. In particular, we find for the (bridge site) adsorption on the unreconstructed 1×1 phase that the initial core level shift of surface Ir atoms is altered by +0.17 eV for each Ir–H bond formed. In the submonolayer regime we find evidence for island formation at low temperatures. For the H-induced deconstructed 5×1-H phase we identify four different surface core level shifts with two of them being degenerate. Finally, for the reconstructed 5×1-hex phase also four surface components are identified, which undergo a rather rigid core level shift of +0.15 eV upon hydrogen adsorption suggesting a similarly homogeneous charge transfer to all Ir surface atoms. Thermodesorption experiments for the 5×1-H phase reveal two different binding states for hydrogen independent of the total coverage. We conclude that the surface always separates into patches of fully covered deconstructed and uncovered reconstructed phases. We could also show by tunneling microscopy that with the desorption of the last hydrogen atom from the deconstructed unit cell the surface instantaneously reverts into the reconstructed state. Eventually, we could determine the saturation coverage upon molecular adsorption for all phases to be θ =1.0ML, θ =0.8ML, and θ ≥1.0ML.

FAU-Autoren / FAU-Herausgeber

Ferstl, Pascal
Professur für Experimentalphysik
Hammer, Lutz Dr.
Lehrstuhl für Festkörperphysik
Heinz, Klaus Prof. Dr.
Naturwissenschaftliche Fakultät
Schneider, M. Alexander Prof. Dr.
Professur für Experimentalphysik

Autor(en) der externen Einrichtung(en)
Lund University / Lunds universitet
Vienna University of Technology


Arman, M.A., Klein, A., Ferstl, P., Valookaran, A., Gustafson, J., Schulte, K.,... Knudsen, J. (2017). Adsorption of hydrogen on stable and metastable Ir(100) surfaces. Surface Science, 656, 66-76.

Arman, Mohammad Alif, et al. "Adsorption of hydrogen on stable and metastable Ir(100) surfaces." Surface Science 656 (2017): 66-76.


Zuletzt aktualisiert 2018-07-11 um 20:50