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Publication Citation: Thermally Assisted Atom Transfer on Surfaces

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Author(s): John William Gadzuk;
Title: Thermally Assisted Atom Transfer on Surfaces
Published: February 01, 2006
Abstract: The low-temperature rates for site-to-site transfer of single atoms and molecules adsorbed on surfaces have been determined in recent scanning tunneling microscopy (STM) studies within the temperature regime where the dominant transfer mechanism changes from mostly activated transmission over to thermally assisted tunneling through the intersite (transition-state) barrier as the temperature is reduced. A model that has provided useful conceptual and quantitative insights into thermally assisted field emission of electrons is used here as the basis for a theory of site-to-site atom transfer in this temperature range where proper account of atomic tunneling and quantum reflection, for energies below and above the transition state barrier, is required. The predicted transfer rates, which are very sensitive to barrier shape as well as height, agree well with those observed in the STM studies of Co and Cu on Cu(111) surfaces in the interesting 4K{less than or equal to}T{less than or equal to}7K transition range which is relevant in the atom-by-atom fabrication of thermally stable surface nanostructures.
Citation: Physical Review B (Condensed Matter and Materials Physics)
Volume: 73
Issue: 8
Pages: pp. 08540-1 - 08540-9
Research Areas: Surface Physics