AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Wednesday Sessions
       Session NS-WeA

Invited Paper NS-WeA5
Physical Processes in Atom Manipulation and Creation of Novel Nanostructures of Co and Cu Atoms on Cu(111) Surfaces*

Wednesday, November 2, 2005, 3:20 pm, Room 210

Session: Nanopatterning and Manipulation
Presenter: J.A. Stroscio, NIST
Authors: J.A. Stroscio, NIST
R.J. Celotta, NIST
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We are studying the interactions involved in STM atom manipulation using Co and Cu atoms on a Cu(111) surface@footnote 1@ and building novel CoCu nanostructures using atom manipulation. The interactions responsible for atom manipulation are investigated by measuring the atom dynamics with a STM using both imaging and tunneling spectroscopy methods. Manipulated atom imaging, where the manipulated atom is rastered in the trapping potential of the STM tip, reveals the binding sites of the substrate. Contrast in this new type of image is due to the tip sensing the presence of the adatom, which can reflect atom motion and a variation in the local potential energy surface. Quantitative measurements of atom dynamics are made by studying the tunneling current noise properties during atom manipulation. Two distinct mechanisms of atom motion can be identified in the noise dynamics; quantum tunneling of the adatom between neighboring lattice sites, and vibrational heating of the adatom by inelastic electron scattering. The magnetic Co atom is a Kondo impurity on Cu(111) surfaces at low temperatures. The interaction between Co and Cu can be tuned by varying the Cu coordination in nanostructures built by atom manipulation. These nanostructures show significant changes in the Kondo density of states resonance as a function of Cu coordination. *This work is supported in part by the Office of Naval Research. @FootnoteText@@footnote 1@J. A. Stroscio and R. J. Celotta, Science 306, 242 (2004).