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Principles of Instrumental Analysis, 6th ed. Chapter 21 2 (d) The kinetic energy of an Auger electron is independent of source energy. Thus, Ek = 1073.5 eV 21-5. (a) Eb = hν – Ek – w = hν - 1052.6 27.8 (Equation 21-2) 34 8 18 9 6.6256 10 Js 2.9979 10 m/s eV = 6.2418 10 0.83393 nm 10 m/nm J = 1486.7 eV hc λ − − × × × × × × Eb = 1486.7 – 1052.6 – 27.8 = 406.3 eV (b) Ek = hν – 406.3 – 27.8 34 8 18 9 6.6256 10 Js 2.9979 10 m/s eV = = 6.2418 10 0.98900 nm 10 m/nm J = 1253.6 eV hchν λ − − × × × × × × Ek = 1253.6 – 406.3 – 27.8 = 819.5 eV (c) By obtaining the peak with sources of differing energy, such as the Al and Mg X- ray tubes. Auger peaks do not change with the two sources, whereas XPS peaks do. (d) From Table 21-2, the N(1s) peak for nitrate ( 3NO− )is shifted by +8.0 eV against the reference while that for nitrite ( 2NO− ) is shifted 5.1 eV. Thus the binding energy for should be 2NO− Eb = 406.3 – (8.0– 5.1)= 403.4 eV 21-6. With EELS, low energy electrons are incident on a surface, and the scattered electrons are detected and analyzed. Energy losses can occur due to vibrational excitation of molecules on the surface. With infrared absorption spectrometry, IR radiation is sent through a the sample and the transmitted IR radiation is measured. With Raman spectrometry, radiation in the visible region is sent through a sample, and the scattered
