Radiation Damage as the High-Resolution Limit in HVEM

Electron microscopy (EM) is concerned fundamentally with the elucidation of the structure of solids, ultimately at the level of atomic resolution. Recent advances [1-3] in the design and construction of magnetic lenses and associated supplies for focusing electrons with energies U substantially greater than 100 keV have enabled utilization of the smaller wavelength of these electrons to lower the resolution limit to 0.2 nm. At this level of structural information, it is necessary to be aware that the same electron/ atom Coulomb interactions which are the origin of ‘elastic’ electron scattering and diffract ion phenomena can be responsible for a substantial perturbation on the positional stability of an atom through the ‘inelastic’ transfer of momentum, directly or indirectly, to the atom nucleus. This is what is meant by radiation damage.