Scanning Electron Microscopy (SEM) is a method that can be used to observe the morphology of a material with magnification that far exceeds the ordinary optical microscope. Conditions to be met by sample material that would be characterized using scanning electron microscopy is should be conductive in order to be able to interact well with the primary electrons from electron gun in the scanning electron microscope. If sample material is not conductive, it should be coated with conductive material (e.g. gold) in order to form thin conductive layer on the surface of sample.
In the scanning electron microscope, electrons originating from the electron gun will strike surface of sample so that there is interaction between electrons originating from the electron gun (called primary electrons) with electrons present in the sample surface produces x-rays, secondary electrons, back Scattered electron and auger electron. Secondary electron is utilized and detected using detector to produce an image of characterized sample.