Practical Electron Microscopy and Database

Based on the theory of the real and imaginary parts of the dielectric function the complex interband transition strength is given by [1]:

            -------------- [4354]

where,
            CV -- conduction-valence bands
            ΔE -- The electron energy loss or photon energy
            m₀ -- The mass of the electron
            h -- Planck’s constant
            ε* -- The complex dielectric function (ε)

Equation [4354] indicates that the real part of the interband transition strength J_CV is proportional to the imaginary part of the dielectric function (ε).

[1] Loughin S, French R H, DeNoyer L K, Ching W-Y and Xu Y-N 1996 Critical point analysis of the interband transition strength of electrons J. Phys. D: Appl. Phys. 29 1740