Interactive TEM guide · No. 4

Elastic vs inelastic scattering: signal or artifact?

Each electron is transmitted, scattered elastically or scattered inelastically. Each outcome is signal in one experiment and background in another.

Every electron that enters your specimen does one of four things: it passes through unscattered, it is scattered elastically by a nucleus, it excites a plasmon in the electron gas, or it knocks out a core electron. Each outcome leaves a different mark in the diffraction pattern (reciprocal space) and the image (real space), and each one is either your signal or your artifact, depending on what you asked the microscope to do.

Scope: everything here applies to any modern 80–300 kV (S)TEM. Where a cure needs optional hardware (an imaging energy filter, a cryo holder, a plasma cleaner), that's noted. Check what your instrument actually has fitted.

Part 1

The scattering channels

Pick a channel. For each one: how strongly it deflects the electron (angle), how much energy it loses (loss), what it adds to the diffraction pattern, what it does to the image in real space, and whether it is signal, artifact, or both.

Part 2

Same specimen, two spaces

All channels act at once in a real experiment. Drive the specimen and the cleanup knobs below and watch the selected-area diffraction pattern and the bright-field image respond together. Each toggle mimics an experimental choice that suppresses or separates one contribution on the real machine; whether a channel is artifact or signal depends on the experiment (TDS is background here and data to a phonon spectroscopist).

Reciprocal space SAED, Cu [001] zone axis

Real space bright-field image

Specimen thickness 60 nm

Zero-loss energy filterneeds an imaging filter fitted (in-column or post-column); without one, thin your specimen

Objective apertureblocks scattered beams → contrast in real space

Cool specimencryo holder damps thermal diffuse scattering (never fully); cold traps fight contamination, not phonons

FIB damage layeramorphous skin from specimen prep (uncheck = low-kV cleanup done)

Contaminationcarbon polymerised under the beam (plasma clean to prevent)

Part 3

The artifact clinic

A list of the things that show up in your data that you did not ask for. Each card: the symptom as you would see it, the scattering physics behind it, and the cure. The micrographs are simulated to show each artifact in isolation. Each card names a textbook or paper with real examples.

Part 4

Signal or artifact? The verdict table

No scattering channel is intrinsically an artifact: "artifact" just means a channel you did not ask for, mixed into the channel you did. The same plasmon that adds haze to your diffraction pattern is the signal in low-loss EELS.

For the physics-curious

References

Show the 8 references

L. Reimer and H. Kohl, Transmission Electron Microscopy: Physics of Image Formation, 5th ed., Springer (2008): elastic and inelastic scattering cross-sections, thermal diffuse scattering and Kikuchi patterns, specimen contamination.
D. B. Williams and C. B. Carter, Transmission Electron Microscopy: A Textbook for Materials Science, 2nd ed., Springer (2009): the chapters on scattering and diffraction, elastic scattering, and inelastic scattering and beam damage.
R. F. Egerton, Electron Energy-Loss Spectroscopy in the Electron Microscope, 3rd ed., Springer (2011): plasmon and core-loss scattering, inelastic mean free paths, and zero-loss filtering.
S. Kikuchi, Diffraction of cathode rays by mica, Proc. Imp. Acad. (Tokyo) 4, 271-274 (1928): the first report of Kikuchi lines.
R. F. Egerton, P. Li and M. Malac, Radiation damage in the TEM and SEM, Micron 35, 399-409 (2004): knock-on damage, radiolysis, heating and contamination, and what reduces each.
J. Mayer, L. A. Giannuzzi, T. Kamino and J. Michael, TEM sample preparation and FIB-induced damage, MRS Bulletin 32, 400-407 (2007): the amorphous surface layer left by the ion beam and low-kV cleanup.
L. Reimer (ed.), Energy-Filtering Transmission Electron Microscopy, Springer (1995): what an imaging energy filter removes from patterns and images.
B. Fultz and J. M. Howe, Transmission Electron Microscopy and Diffractometry of Materials, 4th ed., Springer (2013): scattering amplitudes and the Debye-Waller factor behind thermal diffuse scattering.

Cite this page: Tripathy, Manisha. “Scattering in the TEM: One Beam, Many Fates.” untethered atom, 2026, https://untetheredatom.com/tem/tem-scattering-guide.

BibTeX

@misc{tripathy2026scatteringinthetem,
  author = {Tripathy, Manisha},
  title  = {Scattering in the TEM: One Beam, Many Fates},
  year   = {2026},
  howpublished = {\url{https://untetheredatom.com/tem/tem-scattering-guide}},
  note   = {Interactive teaching resource}
}

Last updated 16 October 2026.