Department of Physics and Astronomy - University of Aarhus - Research activities
Transition-metal oxide surfaces play an important role in a wide range of applications such as heterogeneous catalysis, photo-electrolysis, biocompatibility and sanitary disinfection. Defects such as oxygen vacancies often dominate the electronic and chemical properties of transition-metal oxide surfaces. Our fundamental understanding of point defects is however still very sparse, little is known about the diffusion of defects on transition-metal oxide surfaces. This issue is likely to have profound implications in, for instance, the chemistry related to defects on transition-metal oxide surfaces and the mass transport during the catalytic cycle.
one Abstract:
PHYSICAL REVIEW LETTERS 30 JUNE 1997
Surface Diffusion of Pt on Pt(110): Arrhenius Behavior of Long Jumps
T. R. Linderoth, S. Horch, Erik Lægsgaard, I. Stensgaard, and F. Besenbacher
CAMP and Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
(Received 14 April 1997)
The one-dimensional diffusion of Pt adatoms in the missing row troughs of the (1×2) reconstructed Pt(110) surface is monitored directly from atomically resolved time-lapsed scanning tunneling microscopy images. For this self-diffusion system, it is surprisingly found that not only jumps between nearest neighbor sites but also long jumps, i.e., jumps between next nearest neighbor sites, participate. The hopping rate for these long jumps is found to follow an Arrhenius dependence with an activation barrier for diffusion (Ed2= 0.89 eV) slightly larger than that for single jumps (Ed1= 0.81 eV).
Department of Physics and Astronomy - University of Aarhus - STM Movies
