ABSTRACT
This chapter explores several practical considerations that apply to specimens undergoing microanalysis. Specimens supported on grids should be placed in the holder so that the supported film is facing toward the electron gun and hence toward the detector. In this way there is minimal X-ray absorption by the grid bars and the signal is at its strongest. Many scanning transmission electron microscopy instruments have X-ray detectors fitted, situated close to the specimen, with relatively large solid angles of detection. Specimen tilt is useful for analysis because maximum detection sensitivity is obtained when the incident probe passes along the length of the object under study. Tilting the specimen such that the grain boundary lies parallel to the probe direction will substantially increase the number of atoms lying inside the probe. Tilting the specimen is likely to change the height of the region of interest inside the objective lens and may lead to a defocused image.
