Scanning Electron Microscopy (SEM)

Scanning electron microscopy examines structure by bombarding the specimen with a scanning beam of electrons and then collecting slow moving secondary electrons that the specimen generates. These are collected, amplified, and displayed on a cathode ray tube (a slower version of the picture tube of a television set). The electron beam and the cathode ray tube scan synchronously so that an image of the surface of the specimen is formed. Specimen preparation includes drying the sample and making it conductive to electricity, if it is not already. Photographs are taken at a very slow rate of scan in order to capture greater resolution. SEM is typically used to examine the external structure of objects that are as varied as biological specimens, rocks, metals, ceramics and almost anything that can be observed in a dissecting light microscope. The SRNML has the following SEMs:

JEOL JSM-880 high resolution scanning electron microscope

  • magnification: X 10 to X 300,000)
  • 15 Ångstrom resolution (LaB6 source)
  • backscattered electron detector, transmitted electron detector, electron channelling imaging
  • Double-tilt analytical holder with picoammeter for quantitative X-ray work
  • Kevex X-ray analyzer with IXRF software and digital imaging capability available
  • Equipped for x-ray feature analysis, mapping and quantitative analysis
  • Film support using sheet film or Polaroid is available, but most users opt for digital images
  • CDs and sleeves are provided per each session
JSM-880 SEM

Zeiss DSM-960A SEM

ZEISS DSM-960A scanning electron microscope

  • magnification: X 10 to X 300,000)
  • 70 Ångstrom resolution (approximate)
  • OXFORD Link Pentafet X-ray analyzer with IXRF software imaging capability, feature analysis and quantitative software.
  • microscope used for student instruction
  • Film support using sheet film or Polaroid is available, but most users opt for digital images
  • CDs and sleeves are provided per each session

This microscope joined the lab in 2003 and is the microscope used for instruction in various courses and also the Oklahoma Ugly Bug contests (see http://www.uglybug.org/). The DSM is among the first digital SEMs made. This microscope is a composites of parts of SEMs donated by Conoco-Phillips and the OSBI.


Information is also available on:

Return to the SRNML Home Page.