Reciprocity between the reflection electron microscope and the lowhyphen;loss scanning electron microscope

摘要

The reflection electron microscope imagemdash;or, more correctly, the darkhyphen;field image from a solid specimen in the transmission electron microscopemdash;has certain similarities to the lowhyphen;loss electron image in the scanning electron microscope. These methods arereciprocalin the sense that it is possible to establish an equivalence by reversing the direction of the electrons through the system. In both cases the scanning version is better suited for imaging by means of widehyphen;angle scattering events, while the nonscanning version is better suited for diffraction contrast. The equivalence between these two methods can be established by either a wavehyphen;optical or a geometrical argument.