Skip to main content Accessibility help

Specimen Charging on Thin Films with One Conducting Layer: Discussion of Physical Principles

  • Robert M. Glaeser (a1) (a2) and Kenneth H. Downing (a2)


Although the most familiar consequences of specimen charging in transmission electron microscopy can be eliminated by evaporating a thin conducting film (such as a carbon film) onto an insulating specimen or by preparing samples directly on such a conducting film to begin with, a more subtle charging effect still remains. We argue here that specimen charging is in this case likely to produce a dipole sheet rather than a layer of positive charge at the surface of the specimen. A simple model of the factors that control the kinetics of specimen charging, and its neutralization, is discussed as a guide for experiments that attempt to minimize the amount of specimen charging. Believable estimates of the electrostatic forces and the electron optical disturbances that are likely to occur suggest that specimen bending and warping may have the biggest impact on degrading the image quality at high resolution. Electron optical effects are likely to be negligible except in the case of a specimen that is tilted to high angle. A model is proposed to explain how both the mechanical and electron-optical effects of forming a dipole layer would have much greater impact on the image resolution in a direction perpendicular to the tilt axis, a well-known effect in electron microscopy of two-dimensional crystals.


Corresponding author

Corresponding author. E-mail:


Hide All


Brink, J., Gross, H., Tittmann, P., Sherman, M.B., & Chiu, W. (1998a). Reduction of charging in protein electron cryomicroscopy. J Microsc 191, 6773.
Brink, J., Sherman, M.B., Berriman, J., & Chiu, W. (1998b). Evaluation of charging on macromolecules in electron cryomicroscopy. Ultramicroscopy 72, 4152.
Cazaux, J. (1995). Correlations between ionization radiation damage and charging effects in transmission electron microscopy. Ultramicroscopy 60, 411425.
Downing, K. (1991). Spot-scan imaging in transmission electron microscopy. Science 251, 5359.
Downing, K.H., McCartney, M.R., & Glaeser, R.M. (2004). Experimental characterization and mitigation of specimen charging on thin films with one conducting layer. Microsc Microanal 10, 783789 (this issue).
Jakubowski, U., Baumeister, W., & Glaeser, R. (1989). Evaporated carbon stabilizes thin, frozen-hydrated specimens. Ultramicroscopy 31, 351356.
Joy, D. (1995). Monte Carlo Modeling for Electron Microscopy and Microanalysis. New York: Oxford University Press.
Panofsky, W. & Phillips, M. (1962). Classical Electricity and Magnetism. Reading, MA: Addison-Wesley Pub. Co.
Reimer, L. (1998). Scanning Electron Microscopy: Physics of Image Formation and Microanalysis. Berlin, New York: Springer.


Specimen Charging on Thin Films with One Conducting Layer: Discussion of Physical Principles

  • Robert M. Glaeser (a1) (a2) and Kenneth H. Downing (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed