AES, SAM, SEM
A small spot electron source generates primary electrons of several keV energy that are impinging on a sample surface. It produces an electron core hole. Driven by the Coulomb interaction an electron from a higher electronic state relaxes into this core hole and transfers its energy to another electron, that is finally emitted as the Auger electron, named after Pierre Auger. These electrons are characteristic for an element and can be used for surface chemical analysis.By scanning across the sample a chemical map of the surface is generated with a lateral resolution simlar to the spot diameter of the primary electron source. The Auger electrons are accompanied by secondary electrons, so that a secondary electron micrograph ist also generated in similar lateral resolution.