High transient mobility of chlorine on TiO2(110): evidence for "cannon-ball" trajectories of hot adsorbates

U. Diebold, W. Hebenstreit, G. Leonardelli1, M. Schmid1, and P. Varga1

Department of Physics, Tulane University, New Orleans, LA 70118, U.S.A.
1Institut für Allgemeine Physik, Technische Universität Wien, A-1040 Wien, Austria

Phys. Rev. Lett. 81 (1998) 405-408

Scanning tunneling microscopy was used to study the initial stages of Cl2 adsorption on TiO2(110). Cl atoms adsorb on the rows of 5-fold coordinated surface Ti atoms, and mostly form well separated pairs (average distance 26 Å, atoms can be two or three rows apart). Abstractive adsorption results in 10% single Cl adatoms. We propose that Cl2 dissociates in an approximately upright position. The outer Cl atom is emitted along the bond axis and can surmount the substrate bridging oxygen rows in a "cannon-ball" like trajectory. Channeling along the Ti rows leads to large average Cl - Cl distances.

Corresponding author: U. Diebold. Reprints also available from M. Schmid (schmid< encoded email address >).

Users with online access to Phys. Rev. Lett. can load the article from the publisher.