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Table 3925. Comparison between EELS and AES
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EELS |
AES |
Naming |
Named by the initial state, , e.g. 2p3/2 → 3d5/2 is Lα1 [see page4478] |
Named by initial ionization, filling shell, shell of ejected electron, e. g. KL2L3 [see page4478] |
Quantification |
Less complicated |
More complicated and needs standards |
Sensitivity |
Highly sensitive to low atomic number (Z) elements |
Highly sensitive to low atomic number (Z) elements |
Energy of detected electrons |
Best range: 100 eV to 1, 000 eV |
Energies of Auger electrons: 20–500 eV |
Surface sensitivity |
Not very surface-sensitive |
Highly surface sensitive |
Vacuum |
High vacuum |
Ultrahigh vacuum |
Bulk specimens |
Applicable for reflection EELS (REELS) |
Applicable for "backscattering" detection |
Spatial resolution |
< 1 nm for thin TEM films |
100 nm for bulk specimens; 2 nm for thin films |
Process |
Energy loss process is the first step after interaction of incident electrons with atoms. Refer to Figure 3925 below. |
Auger electron generation can originate from energy loss process of incident electrons. Refer to Figure 3925 below. |
Figure 3925 shows the schematic illustrations of examples of energy loss process of incident electrons (a), x-ray generation (b), and Auger electron generation (c). EKE1 and EKE2 represent the kinetic energies of the two generated SEs. ΔE1 and ΔE2 represent the energy losses of the incident electrons after the incident electrons interact with the electrons in the K and L3 subshells, respectively. E1 and E2 are the binding energies of the two electrons. E0 is the energy of the incident electrons in the EMs. EKE represents the kinetic energy of Auger electrons.
Figure 3925. Schematic illustrations of examples of energy loss process (a), x-ray generation (b), and Auger electron generation (c).
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