TEM Specimens and Images

Abstract

In the transmitted-light microscope, variation of intensity within an image is caused by differences in the absorption of photons within different regions of the specimen. In the case of a TEM, however, essentially all of the incoming electrons are transmitted through the specimen, provided it is suitably thin. Although not absorbed, these electrons are scattered (deflected in their path) by the atoms of the specimen. To understand the formation and interpretation of TEM images, we need to examine the nature of this cattering process.