Mechanisms of radiation damage in beam‐sensitive specimens, for TEM accelerating voltages between 10 and 300 kV

Abstract

Ionization damage (radiolysis) and knock‐on displacement are compared in terms of scattering cross section and stopping power, for thin organic specimens exposed to the electrons in a TEM. Based on stopping power, which includes secondary processes, radiolysis is found to be predominant for all incident energies (10–300 keV), even in materials containing hydrogen. For conducting inorganic specimens, knock‐on displacement is the only damage mechanism but an electron dose exceeding 1000 C cm−2 is usually required. Ways of experimentally determining the damage mechanism (with a view to minimizing damage) are discussed. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.

In Situ Transmission Electron Microscopy Study of Electron Beam-Induced Transformations in Colloidal Cesium Lead Halide Perovskite Nanocrystals

“…28 Knock-on damage involves an irreversible displacement of the nuclei in the specimen, when the transferred energy overcomes the displacement energy of the atoms in the material, and it is dominant at high energy. 26,28,29 Ionization damage (or radiolysis) involves inelastic scattering, and is dominant at low energy.…”

“…26,28,29 Ionization damage (or radiolysis) involves inelastic scattering, and is dominant at low energy. 28,29 In the present case, for a better comprehension of the electron-specimen interaction we evaluated the evolution of halide perovskite NCs, which involved appreciable compositional change, upon electron beam irradiation at two different values of incident electron energy ( E 0 ) (see Figure S1). In particular, we verified that 80 keV electrons cause more effective damage (in terms of loss of Br atoms) than 200 keV electrons, suggesting that radiolysis rather than knock-on is the major mechanism of damage, as expected for both covalent and ionic crystals.…”

Insights into the growth of bismuth nanoparticles on 2D structured BiOCl photocatalysts: an in situ TEM investigation

“…54,56 To confirm the assumed possible knock-on effect, low-voltage TEM observation was performed in another set of experiments. As shown in Fig.…”

Outrun radiation damage with electrons?

“…But in most insulating materials, radiolysis provides a far more efficient damage mechanism; although knock-on damage must occur in organic materials, it is likely to be 10 3 to 10 6 times slower than radiolysis [27]. So in practice, the momentum associated with electrons does not appear to represent a significant additional problem with organic samples.…”