Spectroscopy Auger electron emission

The incoming electron beam interacts with the sample to produce a number of signals that are subsequently detectable and useful for analysis. They are X-ray emission, which can be detected either by Energy Dispersive Spectroscopy, EDS, or by Wavelength Dispersive Spectroscopy, WDS visible or UV emission, which is known as Cathodoluminescence, CL and Auger Electron Emission, which is the basis of Auger Electron Spectroscopy discussed in Chapter 5. Finally, the incoming... 

Fig. 16. Processes involved in Auger electron emission during X-ray photoelectron spectroscopy.

AES atomic emission spectroscopy Auger electron spectroscopy-... 

AEAPS Auger Electron Appearance Potential Spectroscopy, 2 AEES Nuclear Auger Electron (Emission) Spectroscopy ... 

Auger electron spectroscopy is the most common technique for determining the composition of solid and liquid surfaces. Its sensitivity is about 1% of a monolayer, and it is a relatively simple technique to perform experimentally. Auger electron emission occurs in the following manner. When an energetic beam of electrons or X-rays (1000-... 

NEXAFS spectroscopy basically does not require the most sophisticated apparatus to be performed but a source of tunable radiation as that dispensed by a photon factory or synchrotron plant. The experimental station for the study of macromolecular materials requires a UHV system and a detector apparatus for counting the emitted electrons. The primary process in NEXAFS is the core electron excitation into an appropriate final state empty molecular orbital. After excitation, the whole system undergoes relaxation and this can occur through two main decay processes secondary or Auger electron emission and fluorescence emission. Mostly, the detector for NEXAFS uses a simple channeltron tuned for a specific Auger energy or tuned to collect the whole secondary electrons resulting from the relaxation process fluorescence detector are also relatively common alternatively, for sample insulator the measurement of the drain current from the conductor sample holder is often measured examples are displayed in Fig. 4.4. Measurements can be performed on gas, solid and recently liquid state [3]. 

The photoionization process described in the section A Method of Elemental Analysis leaves an ion in an excited state, which may relax in two ways illustrated by Fig. 13a for oxygen (a) electron transition to fiU the position left unoccupied at the lower level, the energy conservation being insured by the emission of a photon this is responsible for X-ray fluorescence, and will not be discussed here and (b) Auger electron emission, which is described using the symbols of energy levels (K, L, M, etc.) used in X-ray spectroscopy. 

Auger electron spectroscopy AES Electron emission from surface atoms excited by electron. X-ray, or ion bombardment Surface composition... 

As indicated in other paragraphs, ionization of atomic inner shells is followed by their reorganization, which may result in X-ray emission and Auger electron emission (see Chapter 2.1.2.2.4, p. 220). In spite of the most frequent predominance of nonradiative processes after an initial vacancy formation in an inner shell. Auger electron spectroscopy (AES) was slow to take its deserved importance as compared to X-ray emission spectroscopy... 

Scanning Auger Electron Spectroscopy (SAM) and SIMS (in microprobe or microscope modes). SAM is the most widespread technique, but generally is considered to be of lesser sensitivity than SIMS, at least for spatial resolutions (defined by primary beam diameter d) of approximately 0.1 im. However, with a field emission electron source, SAM can achieve sensitivities tanging from 0.3% at. to 3% at. for Pranging from 1000 A to 300 A, respectively, which is competitive with the best ion microprobes. Even with competitive sensitivity, though, SAM can be very problematic for insulators and electron-sensitive materials. 

Elastic Recoil Detection Analysis Glow discharge mass spectrometry Glow discharge optical emission spectroscopy Ion (excited) Auger electron spectroscopy Ion beam spectrochemical analysis... 

Ion beam spectrochemical analysis Auger emission spectroscopy Scanning electron microscopy (SEM) Electron microprobe (EMPA) Particle-induced X-ray emission spectroscopy (PIXE)... 

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