Auger electron kinetic energy

The Auger electron kinetic energy is obtained from... 

The shift in measured by XPS core level binding energies between a rare gas such as xenon in the gas phase and adsorbed on a surface results from a combination of chemical shift, local potential at the site of the adsorbate, and stabilization of the photoionization core hole by polarization of the substrate electron density. As discussed in reference (13), the contribution due to substrate polarization is related to the surface electronic polarizability and can be isolated from the other contributions to a good approximation by measurements of the xenon gas phase and adsorbed phase "Auger parameter", a. a is defined as the difference between the (Jkl) core level Auger electron kinetic energy, K (jkl), and the (j) core level photoelectron kinetic energy, K (J). 

The basic equation for Auger electron kinetic energies given above may be modified in a physically realistic way to give the correct expression by the inclusion of an interaction energy, U, such that... 

Figure Al.7.12. Secondary electron kinetic energy distribution, obtained by measuring the scadered electrons produced by bombardment of Al(lOO) with a 170 eV electron beam. The spectrum shows the elastic peak, loss features due to the excitation of plasmons, a signal due to the emission of Al LMM Auger electrons and the inelastic tail. The exact position of the cutoff at 0 eV depends on die surface work fimction.

Figure 14.25 Table of values and plot of the Auger MNN electron kinetic energy for tin and Auger parameter vs. the photoelectron binding energy for the tin 3ds/2 electron in the element and a variety of compounds. The metal and different chemical states of tin in compounds can be readily distinguished. [From Moulder et al., courtesy of Physical Electronics USA, Inc. (www.phi.com).]...

AES Auger electron spectroscopy After the ejection of an electron by absorption of a photon, an atom stays behind as an unstable Ion, which relaxes by filling the hole with an electron from a higher shell. The energy released by this transition Is taken up by another electron, the Auger electron, which leaves the sample with an element-specific kinetic energy. Surface composition, depth profiles... 

If monochromatic X-rays are used as the ionizing radiation the experimental technique is very similar to that for XPS (Section 8.1.1) except that it is the kinetic energy of the Auger electrons which is to be measured. Alternatively, a monochromatic electron beam may be used to eject an electron. The energy E of an electron in such a beam is given by... 

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