Electron Diffraction

Under construction

Electron diffraction is clearly not an imaging mode for an electron microscope. It also differs significantly from the techniques listed under nanoscale analysis in that every TEM is capable of electron diffraction (i.e., no additional equipment such as scanning coils, annular detectors or an energy filter is needed). Thus electron diffraction falls into the grey areas outside of imaging or nanoscale analysis. However, it can be useful when combined with either type of use, and a brief description is provided here.

As with most objects examined using an electron microscope, the scale and resolution of the objects examined using electron diffraction can change by many orders of magnitude. At the large end of this spectrum, electron diffraction information can be in the resolution range of 10's of nm (protein crystal spacings are often this large) and specimen sizes can include single crystals that are 10's of micrometers (or larger) across. At the other end of the spectrum, electron diffraction can yield resolution measured in fractions of an Å and nano-area electron diffraction can analyze samples that are only nm in width. In addition, poly-crystalline materials can cover large areas of an electron microscope grid and produce electron diffraction patterns that resemble the powder diffraction patterns more familiar from X-ray and neutron diffraction studies of powders and micro-crystalline samples.