IBM Journal of Research and Development
IBM Skip to main content
  Home     Products & services     Support & downloads     My account  

  Select a country  
Journals Home  
  Systems Journal  
Journal of Research
and Development
    Current Issue  
    Recent Issues  
    Papers in Progress  
    Search/Index  
    Orders  
    Description  
    Patents  
    Recent publications  
    Author's Guide  
  Staff  
  Contact Us  
  Related links:  
     IBM Research  

IBM Journal of Research and Development  
Volume 39, Number 6, Page 669 (1995)
Proximal probe microscopies
  Full article: arrowPDF   arrowCopyright info





   

The femtosecond field-emission camera, a device for continuous observation of the motion of individual adsorbed atoms and molecules

by G. M. McClelland, H. Heinzelmann, F. Watanabe
A new instrument, the femtosecond field-emission camera (FFEC), has been developed to continuously record the motion of single adsorbed atoms or molecules, with an ultimate achievable time resolution of 10−14 s. In the FFEC, the motion of an adsorbed species modulates a strong 10−5-A field-emission current from a sharp tip. The emitted electrons are focused into a beam, which is swept electrostatically across a detector screen. The tip substrate can be imaged atomically by field ion microscopy. In this paper, the construction and operating principles of the FFEC are described in some detail, and previously published experiments are reviewed. On a <111> W tip, single Cs atoms are observed to jump between sites instantaneously within the 2-ps instrumental resolution. Individual copper phthalocyanine molecules are observed vibrating with respect to the substrate with a period of ≃10 ps. The time resolution of the FFEC is limited principally by the time-of-flight spread of the electrons between the tip and the deflecting field.
Related Subjects: Adsorption; Field emission; Image processing; Physical chemistry; Physics; Surface effects; Surface science