Auger electron spectroscopy facts for kids
Auger electron spectroscopy is a way of telling what chemical elements are at the surface of an object.
When an electron is removed from a core level of an atom, a higher energy level electron may fall in the vacancy. If the energy released by the fall is transferred to another electron, the latter (called Auger electron) will be emitted from the atom, in what is called the Auger effect, after the French physicist who discovered the phenomenon, Pierre Auger. The kinetic energy levels of the Auger electrons depend on the type of the atoms from which the electrons were ejected, and the chemical environment of the atoms. AES consists of bombarding a sample with energetic electrons and measuring the energy of the Auger electrons, obtaining a spectra that can be used to get information about the identity and environment of the emitting atoms.
Images for kids
Figure 4. Fluorescence and Auger electron yields as a function of atomic number for K shell vacancies. Auger transitions (red curve) are more probable for lighter elements, while X-ray yield (dotted blue curve) becomes dominant at higher atomic numbers. Similar plots can be obtained for L and M shell transitions. Coster – Kronig (i.e. intra-shell) transitions are ignored in this analysis.
Figure 2. AES experimental setup using a cylindrical mirror analyzer (CMA). An electron beam is focused onto a specimen and emitted electrons are deflected around the electron gun and pass through an aperture towards the back of the CMA. These electrons are then directed into an electron multiplier for analysis. Varying voltage at the sweep supply allows derivative mode plotting of the Auger data. An optional ion gun can be integrated for depth profiling experiments.
Auger electron spectroscopy Facts for Kids. Kiddle Encyclopedia.