- Auger effect
The Auger effect (pronEng|ˈɔːʒɚ, or Oh' jeh) is a phenomenon in
physicsin which the emission of an electronfrom an atomcauses the emission of a second electron. [GoldBookRef|title=Auger effect|url=http://goldbook.iupac.org/A00520.html] When an electronis removed from a core level of an atom, leaving a vacancy, an electron from a higher energy level may fall into the vacancy, resulting in a release of energy. Although sometimes this energy is released in the form of an emitted photon, the energy can also be transferred to another electron, which is ejected from the atom. This second ejected electron is called an Auger electron. [GoldBookRef|title=Auger electron|url=http://goldbook.iupac.org/A00521.html]
Upon ejection the
kinetic energyof the Auger electron corresponds to the difference between the energy of the initial electronic transitionand the ionization energyfor the electron shellfrom which the Auger electron was ejected. These energy levels depend on the type of atom and the chemical environment in which the atom was located. Auger electron spectroscopyinvolves the emission of Auger electrons by bombarding a sample with either X-rays or energetic electrons and measures the intensity of Auger electrons as a function of the Auger electron energy. The resulting spectra can be used to determine the identity of the emitting atoms and some information about their environment. Auger recombinationis a similar Auger effect which occurs in semiconductors. An electron and electron hole(electron-hole pair) can recombine giving up their energy to an electron in the conduction band, increasing its energy. The reverse effect is known as impact ionization.
The name "Auger effect" comes from one of its discoverers,
Pierre Victor Auger, and not from the similarly-named device, the auger.
The Auger emission process was discovered in the 1920s by
Lise Meitner, an Austrian physicist. The Auger effect was discovered in 1925 by Pierre Victor Augerupon analysis of a Wilson cloud chamberexperiment. High energy X-rays were applied to ionize gas particles and observe photoelectricelectrons. Observation of electron tracks independent of the frequency of the incident photon energy suggested a mechanism for electron ionization that was caused from an internal conversionof energy of from a radiationless transition. Further investigation and theoretical work showed that the effect was a radiationless effect more than an internal conversion effect by use of elementary quantum mechanics and transition rate and transition probability calculations. (ref 1)
*Charge carrier generation and recombination
Auger electron spectroscopy
*"The Auger Effect and Other Radiationless Transitions". Burhop, E.H.S., Cambridge Monographs on Physics, 1952
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