What the TEM can't do
There are some things TEM can't do:
- TEM cannot take colour images. Colour is sometimes added artificially to TEM images.
- TEM cannot image through thick samples: the usual sample thickness is around 100-200nm. Electrons cannot readily penetrate sections much thicker than 200nm.
- A standard TEM cannot image surface information.
- The TEM cannot reliably image charged molecules that are mobile in a matrix. For example, some species (e.g. Na+) are volatile under the electron beam because the negative electron beam exerts a force on charged material.
Where the TEM is not suitable, other techniques should be used. If in doubt consult the Technique Finder on the AMMRF web site.