Skip to main content
Select Source:

field-emission microscope

field-emission microscope (FEM) A type of electron microscope in which a high negative voltage is applied to a metal tip placed in an evacuated vessel some distance from a glass screen with a fluorescent coating. The tip produces electrons by field emission, i.e. the emission of electrons from an unheated sharp metal part as a result of a high electric field. The emitted electrons form an enlarged pattern on the fluorescent screen, related to the individual exposed planes of atoms. As the resolution of the instrument is limited by the vibrations of the metal atoms, it is helpful to cool the tip in liquid helium. Although the individual atoms forming the point are not displayed, individual adsorbed atoms of other substances can be, and their activity is observable.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"field-emission microscope." A Dictionary of Biology. . Encyclopedia.com. 22 Aug. 2017 <http://www.encyclopedia.com>.

"field-emission microscope." A Dictionary of Biology. . Encyclopedia.com. (August 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/field-emission-microscope

"field-emission microscope." A Dictionary of Biology. . Retrieved August 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/field-emission-microscope

field-emission microscope

field-emission microscope: see microscope.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"field-emission microscope." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 22 Aug. 2017 <http://www.encyclopedia.com>.

"field-emission microscope." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (August 22, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/field-emission-microscope

"field-emission microscope." The Columbia Encyclopedia, 6th ed.. . Retrieved August 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/field-emission-microscope