Adsorbed Xe atoms on Si(111)

We have been investigating Xe atoms on an Si(111) surface at T approximate to 80 K in real space with scanning tunneling microscopy by paying attention to their dynamics. Xe atoms were stably adsorbed on defects, as well as step edges, at T approximate to 80 K. We observed the process in which one Xe atom was moving around on a terrace and finally became stable at a step edge, which took more than 10 min. We sometimes observed the movement of Xe islands although the tip-Xe interaction was minimized by choosing a low current of 0.05 nA and a high sample bias voltage of -2.0 V. We successfully moved an Xe atom trapped at a step edge by increasing the tip-atom intel action (a higher tunneling current of 2 nA and a lower sample bias of -0.3 V) as well as other atoms at defects. (C) 1999 Elsevier Science B.V. All rights reserved.