Publication at Faculty of Mathematics and Physics |
2014
Abstract
Low coverage phases of Sn on Si(111)-7x7 were investigated by scanning tunneling microscopy. At room temperature, a single Sn atom is highly mobile inside a half-unit cell of the surface reconstruction.
Its mobility was studied by observing fluctuations of the tunneling current, which allows detecting the movement of the adatom with sub-millisecond resolution. The movement pattern of the atom inside the half-unit cell appears to consist of fast hops between central positions and three corner positions.
The Sn atom was found to be much more mobile inside the faulted half-unit cell, where the hopping frequency is also significantly affected by the presence of the STM tip.