AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS3-TuM

Paper SS3-TuM3
Bonding of Gold Nano-Clusters to Vacancies on Rutile TiO@sub 2@(110)

Tuesday, November 5, 2002, 9:00 am, Room C-112C

Session: Metals, Adsorbates, and Defects on TiO@sub 2@
Presenter: E. Wahlström, University of Aarhus, Denmark
Authors: E. Wahlström, University of Aarhus, Denmark
R. Schaub, University of Aarhus, Denmark
N. Lopez, Technical University of Denmark
A. Ronnau, University of Aarhus, Denmark
J.K. Norskov, Technical University of Denmark
F. Besenbacher, University of Aarhus, Denmark
Correspondent: Click to Email
We have studied the early stages of Au cluster nucleation on defective rutile TiO@sub 2@(110) using scanning tunneling microscopy (STM). STM images and STM movies show a diffusion controlled growth mechanism. Room temperature STM movies show that the smallest stable clusters have a radius > 0.6 nm, while at 140 K not even single gold atoms seem to diffuse on the surface. It is also shown that a correlation exists between a decrease in density of bridging oxygen vacancies and growth of Au clusters at all investigated temperatures. This is direct evidence of a strong interaction between Au atoms and single atomic oxygen vacancies. Density functional theory calculations support these findings.