Sample Artifacts and Damage
The sole reason for using a scanning electron microscope is to obtain accurate, precise and reproducible information about their structure and chemical identity. We seek information either to confirm and extend our existing knowledge about an object or investigate a new and unknown object. The information we obtain is either in the form of a picture (image) or as files of numerical data. We need to be able to validate this information because the processes of obtaining images and data using the SEM are usually very invasive and totally alien to the environment in which we and our specimens exist. We must be satisfied that the procedures used to obtain information do not damage the object or introduce artifacts.
Damage is an unexpected and irreversible change in the object and can occur before and during microscopy. In many cases, damage is very obvious in an image and some examples are shown later in this chapter. However, sometimes the damage is less immediately obvious.