Environmental Scanning Electron Microscopy: - Advantages and Disadvantages

Abstract The possibility of performing scanning electron microscopy under “environmental” conditions (ESEM); where the specimen does not have to be under high-vacuum conditions, or even coated to make it conductive, has existed for several years[l]. Several different flavors of environmental scanning electron microscope now exist, as well as a newer generation of microscope which is capable of imaging at very low accelerating voltages. Techniques for rapidly freezing hydrated specimens and obtaining very high resolution images from them in the SEM have also been improved recently. As a result of all this innovation, it is now possible to examine many classes of specimens in the SEM that were previously thought to be impossible to image (or at least not worthwhile frying). Among the advantages of the environmental SEM are the fact that images of non-conductive surfaces can be obtained without the necessity for additional sample coating. This can be especially important in dynamic experiments, and hot-stage work, where the presence of a surface coating may substantially affect the samples behavior