Electron Microscopes

Adjunto:

• Light microscopes

1. Advantages
   1. Higher resolution
   2. Higher magnification
   3. Fine detail can be observed
   4. SEM can provide 3D image
2. Disadvantages
   1. Specimen is dead
   2. Natural colours can not be seem
   3. Specimen needs to be dehydrated
   4. Expensive
   5. Not portable
   6. Technical expertise required
   7. There is likely to be artifacts

      Nota:

      • Artifact - A structure that is not part of the specimen.
   8. Heat is generated
   9. Vacuum pump required
   10. Specimen and electrons need to be contained
3. There are two types of electron microscopes
   1. Scanning Electon Microscopes
      1. Images are 3D
         1. Depth of field
         2. Internal structures can't be seen
      2. Resolution = 0.5 nm
         1. Cannot achieve same resolution as TEM
      3. Magnification = x 100,000
   2. Transmission Electron Microscopes
      1. Images are 2D
      2. Internal structures can be seen
      3. Resolution = 0.1 nm
      4. Magnification = x 500,000