Table 958. Comparison between different correction methods.
Method 
Correction principle and advantages 
Drawbacks 

This method is based on the approximation that the probability of electrons, entering the anglelimiting aperture is the same for both elastic and inelastic scattering processes 
This assumption is inaccurate in most cases since their scattering probabilities dependence on many factors such as TEM sample thickness and atomic numbers of the materials 
Mixed scattering
[1, 3] 
Corrections of both elastic and inelastic scattering effects had been considered 
i) The scattering is assumed to occur with the same crosssection as the average scattering crosssection, which is oversimplified
ii) No existing model to simulate the elastic scattering correction on complex materials by take the effects of all the different elements in the TEM sample 
Ratio method [1, 5] 
This method is based on the ratios of crosssections and integrated intensities of two elements 
Absolute concentration cannot be obtained 
Elastic scattering [4] 
Correction of elastic scattering effect had been considered 
No existing model to simulate the elastic scattering correction on complex materials by take the effects of all the different elements in the TEM sample 
Plasmon shift correction [2] 
Plasmon shift correction, and
double scattering angular correction for small values of collection aperture (<10 mrad) 
i) Errors caused by multiple correction to the same scattering
ii) Correction of elastic scattering effect had not been considered 

i) Correction of inelastic scattering has been considered.
ii) Crosssection models: HartreeSlater, Hydrogenic, Hydrogenic (white lines)
iii) Areal Density can be evaluated. 

Powerlaw: better for background fitting for thin TEM sample and high energy core losses 

Software (DigitalMicrograph, DM) uses atomic cross sections that do not contain any nearedge fine structure. 
1^{st} order log polynomial: better for background fitting immediately after plasmon tail and very thick TEM sample 
In Table 958, the mixed scattering method employed elastic and inelastic effects to correct the thickness effect of TEM sample. In this method, the coreloss and lowloss (plasmon) scatterings with the same energy window were taken into account in simple formula for the calculation of Areal Density, N.
In the thickness correction methods listed in Table 958, Mixed Scattering [1] and Elastic Scattering [4] methods considered the effect of angular distribution of elastic scattering. However, all of them do not have any existing model to simulate the elastic scattering correction on complex materials by take the effects of all the different elements in the TEM sample.
In the plasmon shift correction method [2], two correction terms, one related to a loss of collection efficiency after a shift in energy caused by multiple scattering and one related to a convolution of angular collection efficiencies caused by double scattering, had been employed for correction of coreloss signal. However, in this method, errors can be caused by multiple correction to the same scattering, and correction of elastic scattering effect had not been considered.
The advantage of Ratio Method is based on the ratios of crosssections and integrated intensities of two elements:
 [958] where,
σ_{A}(β,Δ) and σ_{B}(β,Δ)  the crosssection per atom for innershell scattering through angles up to a semiangle β.
I_{A}(β,Δ) and I_{B}(β,Δ)  the integrated intensity under the particular excitation edge, after subtracting a background.
This method is used to cancel the effects of several artefacts such as thickness effects and diffraction contrast. In this method, the lowloss region need not be measured unless it is required for deconvolution. However, this method cannot provide absolute concentrations without additional information.
[1] R.F. Egerton, Formulae for LightElement Microanalysis by Electron EnergyLoss Spectrometry, Ultramicroscopy 3 (1978) 243.
[2] A. P. Stephens, Quantitative microanalysis by electron energyloss spectroscopy: Two corrections, 5 (1–3) (1980), 343349.
[3] R. F. Egerton, The Range of Validity of EELS Microanalysis Formulae, Ultramicroscopy 6 (1981) 297300.
[4] K. Wong and R. F. Egerton, Correction for the effects of elastic scattering in coreloss quantification, Journal of Microscopy, 178 (3), (1995), 198207.
[5] P. J. Thomas and P.A. Midgley, An introduction to energyfiltered transmission electron microscopy, Topics in Catalysis, 21 (4), (2002), 109.
