Practical Electron Microscopy and Database

In energy filtering transmission electron microscope (EFTEM) measurements, a method for correcting plural inelastic scattering effects in elemental maps was proposed by using just two energy windows: one above and one below a core-edge in the electron energy loss spectrum (EELS). [1] This method was tested in mapping low concentrations of phosphorus in biological samples by the following steps:
         i) single scattering EELS distributions are obtained from specimens of pure carbon and plastic embedding material.
         ii) spectra are calculated for different specimen thicknesses t/λ. Here, λ is inelastic mean free path.

In this method, standard curves are generated for the ratio k₀ of post-edge to pre-edge intensities as a function of relative specimen thickness t/λ. The thickness effects in a two-window map are then corrected by successive acquisition of zero-loss and unfiltered images.

[1] M. A. Aronova, Y. C. Kim, G. Zhang, and R. D. Leapman, Quantification and Thickness Correction of EFTEM Phosphorus Maps, Ultramicroscopy, 107(2-3): 232–244, (2007).