Premium
Non‐contact AFM images measured on Si(111)√3×√3‐Ag and Ag(111) surfaces
Author(s) -
Sugawara Y.,
Minobe T.,
Orisaka S.,
Uchihashi T.,
Tsukamoto T.,
Morita S.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199905/06)27:5/6<456::aid-sia536>3.0.co;2-i
Subject(s) - van der waals force , chemical force microscopy , dangling bond , atomic force microscopy , chemistry , atom (system on chip) , conductive atomic force microscopy , materials science , molecular physics , crystallography , analytical chemistry (journal) , nanotechnology , silicon , non contact atomic force microscopy , molecule , optoelectronics , organic chemistry , chromatography , computer science , embedded system
We investigated the force interactions between a Si tip and aSi(111)√3×√3‐Ag surface, as wellas between a Si tip and an Ag(111) surface, usingnon‐contact atomic force microscopy (AFM) operatingin ultrahigh vacuum (UHV). The AFM images on theSi(111)√3×√3‐Ag surface showedthree types of contrast that depended on the distance between a tipand a sample surface: at a tip–sample distance of 0.1–0.3nm the AFM image showed a honeycomb arrangement, at atip–sample distance of 0–0.05 nm the image showed theperiodic structure of a triangle, consisting of three bright spotswith relatively strong contrast, but at a distance of 0.05–0.1nm the image contrast seemed to be intermediary between the other twotypes of contrast. When the tip is far from the sample surface, thetip–sample interaction force is dominated by physical bondinginteractions such as Coulomb and/or van der Waals forces betweenthe tip apex Si atom and the Ag trimer on the sample surface. On theother hand, just before contact, the tip–sample interactionforce is dominated by chemical bonding interaction due to the onsetof hybridization between the dangling bond of the tip apex Si atomand the orbital of the Si–Ag covalent bond on the surface.Furthermore, atomic resolution imaging of a pure metallic surface ofAg(111) was achieved, suggesting that non‐contactAFM has potential for the investigation of a pure metallic surface.Copyright © 1999 John Wiley & Sons, Ltd.