In some cases, EELS artifacts induced by beam damage on the specimens in TEM measurements can be monitored by observation of energy-loss near-edge structure (ELNES), for instance, in the damage process of CeO₂ specimens. The electron beam damage induces the changes in the spectral shape of a CeO₂ specimen in thickness of 0.17λ within a few seconds. λ is inelastic mean free path. Figure 1301 shows the damage sequence from fresh CeO₂ (A) to damaged CeO₂ (H) with such thickness. After H, the edge showed no further changes with increase of electron dose. The M₅ and M₄ maxima and the peaks Y and Y' are associated with Ce⁴⁺. The electron-beam damaged CeO₂ presents Ce M_4,5 and O K-edge shapes that are consistent with reduction to a Ce³⁺ oxide. During the beam-damage process the spectrum of CeO₂ changes as below:
         i) Decreases in energies of the M₅ and M₄ maxima,
         ii) Changes in shape of the near-edge structure,
         iii) Inversion of the M₅ to M₄ branching ratio,
         iv) Increase in the M₅ to M₄ area ratio.

Figure 1301. The damage sequence from fresh CeO₂ (A) to damaged CeO₂ (H) in thickness of 0.17λ. The estimated doses in each case are (A) 3 x 10⁵ e/Ų; (B) 6 x 10⁵ e/Ų; (C) 2 x 10⁶ e/Ų; (D) 3 x 10⁶ e/Ų; (E) 7 x 10⁶ e/Ų; (F) 1 x 10⁷ e/Ų; (G) 2 x 10⁷ e/Ų; and (H) 5 x 10⁷ e/Ų. [1]

[1] 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.