AVS 47th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP18
Temperature-induced Morphology Changes for 1D Pt Islands on Pt(110)-(1x2)

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: T.R. Linderoth, University of Aarhus, Denmark
Authors: T.R. Linderoth, University of Aarhus, Denmark
S. Horch, University of Aarhus, Denmark
L. Petersen, 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
The Pt/Pt(110)-(1x2) system has proven a fascinating one-dimensional model system for the study of adatom dynamics by time-resolved STM. At temperatures between 290-380 K, isolated ad-atoms and islands are restricted to the missing-row troughs where atoms show a quasi-1D diffusion behaviour@footnote 1@ while islands migrate along the troughs by a so-called "leap-frog" mechanism.@footnote 2@ Here we wish to present the results of quench-and-look experiments initiated to investigate ripening in this seemingly 1D system. When a surface with 1D Pt islands situated in the missing-row troughs is annealed at 369-395 K, we find: (a) an increase in the mean island size (coarsening) and (b) a surprising island restructuring, where adatoms move from the troughs up on top of the islands. Quantitative analysis of these findings and comparison to the known rates for island diffusion and other relevant kinetic processes interestingly reveal that the Pt/Pt(110)-(1x2) system can NOT be treated as purely 1D at the higher adatom coverages of 27±4 % used in the present experiments. Dynamic STM data, acquired at these higher adatom coverages, provides direct evidence for novel atomic-scale mechanisms leading to inter-trough mass transport. @FootnoteText@ @footnote 1@ Phys. Rev. Lett. 78, 4978 (97). @footnote 2@ Phys. Rev. Lett. 82, 1494 (99).