AVS 51st International Symposium
    Surface Science Friday Sessions
       Session SS1-FrM

Paper SS1-FrM4
H@sub 2@O/D@sub 2@O Dimer Formation on Pd (111) Studied by STM

Friday, November 19, 2004, 9:20 am, Room 210B

Session: Hydrated Surface Phenomena
Presenter: E. Fomin, University of California at Berkeley
Authors: E. Fomin, University of California at Berkeley
M. Tatarkhanov, University of California at Berkeley
D.F. Ogletree, Lawrence Berkeley National Laboratory
M. Salmeron, Lawrence Berkeley National Laboratory
Correspondent: Click to Email
We have studied the adsorption and dynamics of H@sub 2@O and D@sub 2@O molecules and dimers on Pd(111) using variable low temperature (@>=@ 25 K) scanning tunneling microscopy (STM). At higher temperatures (>35K) dimers are formed by thermally activated diffusion. At lower temperatures dimer formation was induced by inelastic ecletron tunneling. We measured the hopping rate of single molecules and dimers and discovered that diffusion coefficients differ by 4 orders of magnitude. Recent theoretical analysis@footnote 1@, proposed to explain this effect implies isotopic change in a diffusion coefficient for D@sub 2@O dimers compared to H@sub 2@O ones. In our experiments we were unable to detect this difference. @FootnoteText@ @footnote 1@Ranea VA. Michaelides A. Ramirez R. de Andres PL. Verges JA. King DA. Water dimer diffusion on Pd{111} assisted by an H-bond donor-acceptor tunneling exchange - art. no. 136104. [Article] Physical Review Letters. 9213(13):6104, 2004 Apr 2.