Jannik C. Meyer Created 2026-10-20 Updated 2026-11-05
A researcher who coauthored quantitative measurements of electron-beam damage in graphene. Counting displaced carbon atoms as beam energy and dose changed gave a displacement cross section. Comparing carbon isotopes helped distinguish nuclear collisions from other damage mechanisms. Including lattice motion was necessary to explain the results, making the microscope itself a controlled scattering experiment.[ref]
Use low-voltage, preferably aberration-corrected HRTEM, with about 60–80 kV as a defensible operating range. An approximately 80 kV starting point balances useful lattice resolution against carbon displacement damage; use the lower end if the instrument still resolves the lattice and defect stability is the priority.
A higher accelerating voltage reduces the electron wavelength, but can remove carbon atoms by knock-on displacement. Measurements on pristine single-layer graphene show a strong increase in displacement probability above the vicinity of 80 kV, so simply selecting a conventional 200–300 kV setting is a poor way to preserve the original lattice.[ref]
Accurate Measurement of Electron Beam Induced Displacement Cross Sections for Single-Layer Graphene by Jannik C. Meyer and others. Beam-energy dependence of displacement cross sections, Physical Review Letters 108, 196102
reduced graphene oxide is already defective and chemically modified. Its vulnerable sites need not share the pristine-graphene threshold, and ionization, contamination and chemical etching remain possible at low voltage. Minimize dose, spread the beam while aligning and compare successive short exposures. The voltage choice suppresses one damage mechanism; it does not guarantee damage-free imaging.