Lawrenz, M.; Kratzer, Peter; Schwalb, C. H.; Dürr, M.; Höfer, U.:
Diffusion Pathways of Hydrogen across the steps of a vicinal Si(001) surface
2007
In: Physical Review B, Band 75 (2007), 125424/1-6
Artikel/Aufsatz in Zeitschrift2007Physik
Titel:
Diffusion Pathways of Hydrogen across the steps of a vicinal Si(001) surface
Autor(in):
Lawrenz, M.; Kratzer, PeterLSF; Schwalb, C. H.; Dürr, M.; Höfer, U.
Erscheinungsjahr
2007
DOI:
Erschienen in:
Titel:
Physical Review B
in:
Band 75 (2007), 125424/1-6

Abstract:

Hydrogen diffusion across DB steps on Si(001) surfaces is investigated by means of variable-temperature scanning tunneling microscopy and first-principles calculations. Experimentally, the hopping rate for diffusion from the step sites to the Si dimers of the upper terrace was found to be more than one order of magnitude higher than that for diffusion to the lower terrace. This clear preference, opposite to the trend for the respective binding energies, is explained by first-principles calculations that identify a metastable intermediate to be responsible for the unexpected lowering of the energy barrier for upward diffusion.