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The elements with larger atomic number (Z) has stronger elastic and thermal diffuse scattering and thus, a solid composed of element with larger Z can have larger mean free path value λ, i.e. weaker inelastic scattering.
Figure 2880 shows the experimental values of λ_{el} [1] and λ_{in}(Z) [2] as oscillatory functions of Z for Z > 20. Comparison of λ_{el} and λ_{in} values suggests that the elastic component should dominate scattering of incident highenergy electrons for most inorganic solids and of incident electrons penetrating thin TEM specimens.
Figure 2880. The mean free path of elastic scattering λ_{el} of 200 keV electrons (solid squares) [1] and that of inelastic values λ_{in} (open circles) (Adapted from [2]).
[1] Konstantin Iakoubovskii and Kazutaka Mitsuishi, Elastic scattering of 200 keV electrons in elemental solids: experimental observation of atomicnumberdependent oscillatory behavior, J. Phys.: Condens. Matter 21 (2009) 155402.
[2] Iakoubovskii K, Mitsuishi K, Nakayama Y and Furuya K (2008) Phys. Rev. B 77, 104102.
