Examples of Collection and Convergence Semiangles used in EELS
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EELS and EFTEM signals in TEM are always obtained from inelastic scattered electrons at small scattered angles (< 1°). Table 4715 lists examples of collection and convergence semiangles used in EELS.

Table 4715. Examples of collection and convergence semiangles used in EELS.

Materials
Convergence Semiangle
Collection Semiangle
Probe current
Special considerations
Reference
Oxidic materials
≤ 1.5 mrad
7.6 mrad
[1]
Pb(Zr0.3Ti0.7)O3 (PZT)
8.8 mrad
18 mrads
~0.02 nA
Reduces damaging the PZT film while still obtaining reasonable signal to noise
[3]
Cerium
16 mrad
11 mrad
5 nA
[2]

 

 

 

 

 

 

 

 

[1] Optimization of the Signal to Noise Ratio in EFTEM Elemental Maps with Regard to Different Eonization Edge Types G. Kothleitner and F. Hofer, Micron Vol. 29, No. 5, pp. 349–357, (1998).
[2] L.A.J. Garvie and P.R. Buseck, Determination of Ce4+/Ce3+ in electron-beam-damaged CeO2 by electron energy-loss spectroscopy, Journal of Physics and Chemistry of Solids 60 (1999) 1943–1947.
[3] Harkins, P. and MacKenzie, M. and Craven, A.J. and McComb, D.W. (2008) Quantitative electron energy-loss spectroscopy (EELS) analyses of lead zirconate titanate. Micron, 39 (6). pp. 709-716. ISSN 0968-4328.

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