Scanning Electron Microscopy (SEM)

An SEM image is formed by a beam of electrons focused to a few billionths of a meter that is swept across the surface of a sample in a series of stacked rows until a complete two dimensional pattern is formed. As the beam strikes solid electrons are emitted from the specimen and those particles are collected to form an image. The image shown on the right is therefore called a “secondary electron image” and shows the topography of a material magnified up to 100,000s of times!

Click to see a series of SEM images at progressively higher magnification.