AVS 46th International Symposium
    Surface Science Division Monday Sessions
       Session SS1+EM-MoA

Paper SS1+EM-MoA8
High-Pressure STM Studies of Pt Nano-clusters on Al@sub 2@O@sub 3@/NiAl(110)

Monday, October 25, 1999, 4:20 pm, Room 606

Session: Metals on Oxides
Presenter: L. Österlund, University of Aarhus, Denmark
Authors: L. Österlund, University of Aarhus, Denmark
M.O. Pedersen, University of Aarhus, Denmark
P. Thostrup, University of Aarhus, Denmark
K.H. Hansen, University of Aarhus, Denmark
E. Laegsgaard, University of Aarhus, Denmark
I. Stensgaard, University of Aarhus, Denmark
F. Besenbacher, University of Aarhus, Denmark
Correspondent: Click to Email
A novel system in which an STM is incorporated into a high pressure cell has been constructed. The system permits in-situ studies of surfaces with atomic resolution at pressures ranging from UHV to one atmosphere. In the present paper, we have investigated the morphology and structure of well-ordered Pt nano-clusters deposited on thin layers of aluminum oxide created by oxidation of NiAl(110). >From the shape, i.e. the height and width, and from atomic resolved images of the top facets of the clusters, we can quantitatively determine the adhesion energy of the metal cluster to the oxide, using calculated surface free energies for the cluster facets. We have investigated the change in the morphology of the Pt nano-clusters exposed to up to 1 bar of hydrogen and oxygen.