1.
Science
; 289(5478): 422-426, 2000 Jul 21.
Article
in English
| MEDLINE
| ID: mdl-10903196
ABSTRACT
The atomic force microscope images surfaces by sensing the forces between a sharp tip and a sample. If the tip-sample interaction is dominated by short-range forces due to the formation of covalent bonds, the image of an individual atom should reflect the angular symmetry of the interaction. Here, we report on a distinct substructure in the images of individual adatoms on silicon (111)-(7x7), two crescents with a spherical envelope. The crescents are interpreted as images of two atomic orbitals of the front atom of the tip. Key for the observation of these subatomic features is a force-detection scheme with superior noise performance and enhanced sensitivity to short-range forces.
2.
Phys Rev B Condens Matter
; 45(23): 13815-13818, 1992 Jun 15.
Article
in English
| MEDLINE
| ID: mdl-10001493