Abstract
Scanning tunneling microscopy studies of etching of show that the rate of terrace pit formation goes through a maximum for surface coverages of , in contrast to predictions of conventional models. Using recently calculated energies for different possible surface configurations, we show that a key component in desorption is the formation of a single-atom vacancy adjacent to a volatile unit. The demonstration of vacancy-assisted reaction establishes a self-limited reaction and the sequence of events leading to desorption.
- Received 20 July 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.568
©1999 American Physical Society