AVS 57th International Symposium & Exhibition
    Surface Science Tuesday Sessions
       Session SS-TuA

Paper SS-TuA11
Adsorbate Distribution and Dynamics inside Nanometer-Scale Metal Facets

Tuesday, October 19, 2010, 5:20 pm, Room Picuris

Session: Chemical Dynamics at Surfaces
Presenter: J. Wyrick, University of California at Riverside
Authors: J. Wyrick, University of California at Riverside
Z.H. Cheng, University of California at Riverside
M. Luo, University of California at Riverside
D.Z. Sun, University of California at Riverside
D.H. Kim, University of California at Riverside
Y.M. Zhu, University of California at Riverside
W.H. Lu, University of California at Riverside
K. Kim, University of Maryland
T.L. Einstein, University of Maryland
L. Bartels, University of California at Riverside
Correspondent: Click to Email
We use low temperature scanning tunneling microscopy to investigate the diffusion and arrangement of CO molecules adsorbed on Cu(111) facets of ~4 nm diameter formed by self-assembly of a honeycomb network of anthraquinone molecules. CO molecules and adlayers exhibit properties under such nanoscale confinement that markedly depart from those of extended adlayers: a) the confinement stabilizes dislocation lines (anti-phase domain boundaries) in the adlayer that affect roughly ¼ of the adsorbed molecules; b) confinement prevents the formation of dense islands of adsorbed molecules, depending on coverage either causing dispersion of vacancies in the adlayer or preventing the growth of molecular islands; c) at a coverage of just a few molecules on the facet, we observe that a molecular shell structure is formed, resembling in its underlying mathematics the atomic model. Confined structures are an ideal test bed for measurement of the coverage dependence of molecular diffusion and in this study we find a reduction of the diffusion barrier at a slope of 57%/ML.