Practical Electron Microscopy and Database

In Transmission Electron Microscopy (TEM), the kinetic energy of electrons after passing through a specimen is a crucial factor that influences image formation and the analytical capabilities of the technique. When a high-energy electron beam interacts with a thin specimen, electrons can lose energy through various inelastic scattering processes, such as plasmon excitation, electron-electron interactions, and phonon excitations. The extent of energy loss depends on the material's composition, thickness, and the specific interactions occurring within the sample. Electrons that have lost significant energy will appear darker in energy-filtered TEM images, allowing for contrast based on the specimen's composition and thickness. By analyzing the kinetic energy of these transmitted electrons, particularly through techniques like electron energy loss spectroscopy (EELS), researchers can gain valuable information about the material’s electronic structure, bonding, and chemical composition. The distribution of electron energies after passing through the specimen also affects the resolution and contrast of TEM images, making the understanding and control of this kinetic energy distribution critical for accurate and high-quality imaging.

The kinetic energy of electrons after passing the TEM specimen is given by their incident energy E₀ minus any energy loss ΔE occurring in the specimen.