Abstract
The dissociation of on a Pt(111) surface was studied by variable temperature scanning tunneling microscopy at 150–106 K. The two oxygen atoms created by the dissociation appear in pairs, with average distances of two lattice constants. Since thermal random walk sets in only at around 200 K, with a diffusion barrier of 0.43 eV and a preexponential factor of , the distribution of distances at around 160 K evidences nonthermal processes during the dissociation. It is concluded that transient ballistic motion exists, where the short range traveled is in agreement with recent molecular dynamics studies.
- Received 23 February 1996
DOI:https://doi.org/10.1103/PhysRevLett.77.123
©1996 American Physical Society