title: Hard repulsive barrier in hot adatom motion during dissociative adsorption of oxygen on Ag(100).
abstract: Random pairing simulation and low temperature scanning tunneling microscopy (STM) are used to investigate the detailed O(2) dissociative adsorption processes at 200 K for various coverages. The distribution of oxygen adatoms shows a strong repulsion between the adsorbates with a radius of approximately 0.8 nm. The comparison between STM results and simulation reveals two prominent pairing distances of 2 and 4 nm and their branching ratio is about 2:1. These findings shed new light on the origin of the large intrapair distances found and on the process behind the empirical "eight-site rule."
authors.affiliation: Institute of Physics, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan.
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Hsieh
authors.forename: Deng-Sung
authors.initials: DS
authors.lastname: Lin
authors.forename: Heiko
authors.initials: H
authors.lastname: Gawronski
authors.forename: Karina
authors.initials: K
authors.lastname: Morgenstern