The seminar entitled Damage of sensitive specimens by electron and ion beams will be given by Dr. Ondřej L. Sháněl from ThermoFisher Scientific, Czechia on April 9, 2026, at 10:00 am in the IPM lecture hall. The seminar will be held in English.
This presentation examines how electron elastic and inelastic scattering in thin (S)TEM specimens drives three coupled pathways – beam heating, electrostatic charging, knock-on displacement, and radiolysis (via electron-hole and secondary-electron production) – and how their spatial and temporal dynamics control dose-limited resolution. The key message for damage reduction is that sensitivity depends on how the dose is delivered, not only the total dose and the sample type.
Principles for various sample-damage mechanisms and sample types (conductors, insulators, organics, and inorganics), both theoretical and supported by experimental results, are discussed, along with recommended acquisition strategies to minimize sample damage and maximize the signal-to-noise ratio.
The second part of the presentation examines how ion-sample interactions during lamella preparation differ from those with electrons. Theoretical conclusions are supported by practical results and recommended milling strategies are introduced to suppress unwanted effects.
