Abstract
A single stable adatom on a {110}-type plane of a tungsten tip is created via field-evaporation in a field-ion microscope (FIM) operating at room temperature. This single adatom has sufficient surface mobility at room temperature and migrates, in one-dimension, along a 〈111〉-type direction toward an edge of a {110}-type plane, due to the existence of an electric field gradient. The plane edge has a higher local electric field than its center, since it has a higher local geometric curvature. This result implies that the stable position of a single adatom during a scan of a scanning tunneling microscope (STM) tip on a surface is at the edge and not at the center of a {110}-type plane at room temperature. Therefore, the electron wave function of a tip is not symmetric and this fact should be taken into account in a careful analysis of STM images. Also a tip with a dislocation emerging at a {110}-type plane is suggested as an improved STM tip configuration, as the step at the surface, created by the intersection of the dislocation with it, is a perpetual source of single adatoms.
Original language | English (US) |
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Pages (from-to) | 97-101 |
Number of pages | 5 |
Journal | Metals and Materials International |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2004 |
Funding
We thank Prof. G. B. Olson and Dr. T. J. Kinkus for kindly letting us utilize the VG-100 atom-probe field-ion microscope for this research. This work was supported by the Materials Research Laboratory program of the National Science Foundation, at the Materials Research Center of North-western University, under Award No. DMR-9120521.
Keywords
- Adatom
- Dislocation
- Field-ion microscopy
- Scanning tunneling microscopy
- Tungsten tip
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry