Auger electron

When an atom at an excitation state makes a transition to the ground state, if its energy is not used to emit characteristic X-rays but used to emit an electron in the atom, the emitted electron is called "Auger electron." The Auger electron energy is characteristic of an element and the escape depth of the Auger electron is very small (0.5 nm to several nm). Thus, the Auger electron is utilized for qualitative and quantitative compositional analysis and electronic structure analysis (analysis of chemical-bonding states) on top surfaces of solids. The accuracy of Auger electron spectroscopy is about 10%.