Scanning force imaging of atomic size defects on the CaF2 (111) surface

Citation
M. Reichling et C. Barth, Scanning force imaging of atomic size defects on the CaF2 (111) surface, PHYS REV L, 83(4), 1999, pp. 768-771
Citations number
10
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
83
Issue
4
Year of publication
1999
Pages
768 - 771
Database
ISI
SICI code
0031-9007(19990726)83:4<768:SFIOAS>2.0.ZU;2-6
Abstract
Cleaved (111) surfaces on CaF2 were imaged with scanning force microscopy o perated in the dynamic mode in ultrahigh vacuum. Imaging the pristine surfa ce reveals an atomic scale contrast with the structure expected For the flu orine terminated surface. We always reproduced the perfect surface periodic ity never observing stable defects. However, after exposing the surface to 280 L of oxygen while constantly scanning, we detected,stable atomically re solved defects that are assigned to OH- groups incorporated into the surfac e. We could identify a jump of one of the groups from one atomic cell to th e next. The observed contrast at regular lattice sites as well as at defect s is discussed and qualitatively explained.