Electron Microscopical Techniques For The Observation Of Cavities

SUMMARY The full range of methods by means of which cavities can be examined using a transmission electron microscope are reviewed. Different techniques are required in different circumstances and the extent to which a quantitative interpretation can be given is discussed for a number of examples. These range from the use of structure factor contrast for relatively large pores through the use of Fresnel contrast for intermediate sized pores with a dimension in the 0·4–20 nm range to elastic side band imaging and atomic resolution techniques for pores with sizes less than about 0·6 nm.