Damage by Induced Electric Field versus Radiolysis

Radiolysis has been the most referred mechanism to interpret damage phenomena in electron microscopy, especially in semiconductor and insulator materials. This type of damage is initiated from the electronic excitation and ionization by beam electrons. In radiation chemistry, the original concept of radiolytic process results in the cleavage of chemical bond(s) due to exposure to ionizing radiation, and forms radicals. These radicals are highly reactive. The main difference between radiolysis and ionization is that in the former the radical has at least one unpaired electron and this molecule or atom does not carry a charge, while in the latter the ion is either positively or negatively charged due to the loss or gain of an electron Obviously the radiolytic process in radiation chemistry is not the same as what we meant in TEM, in which beam damage is not caused by chemical reaction (with nearest rigid atoms) but by displacement of atom. In rigid solids, the mechanism should be able to provide explicitly how the atom acquires momentum to displace, rather than how the chemical bond breaks. Unfortunately, only a few have addressed this in details among a vast number of publications.