Practical Electron Microscopy and Database

An Online Book, Second Edition by Dr. Yougui Liao (2006)

Practical Electron Microscopy and Database - An Online Book

Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix

Plasmon Peaks from Thick TEM Samples

For thick TEM samples, an incident electron can excite several plasmons and multiple peaks can occur, for instance, two or more plasmons can be excited by a single primary electron, inducing double and/or triple plasmon peaks in the EELS spectrum.

A thin specimen can avoid multiple scattering which obscures the core-loss edges. That is, the sample should be so thin that the plasmon peak is smaller than one-tenth of the zero loss.

The 3rd plasmon peak normally is not significant unless the thickness is approximately equal to the plasmon mean free path of the analyzing materials.