Back-scattered electrons

Impacting primary electrons (PE) are elastically distributed in the atom nucleus area. The higher the positive charge, the stronger the PE deflection at the atom nucleus This helps to scatter more electrons back from the sample surface with increasing atomic numbers (increasing atomic weight). These areas are displayed with a brighter color → Material contrast.

In addition, the back-scattering coefficient depends on the crystal orientation → Orientation contrast.

Additional references:
Electron microscope
Electron microscopy
Electron probe micro analysis
Energy dispersive x-ray spectrometry
Scanning electron microscope
Secondary electrons
Wave-length dispersive x-ray spectrometry

Literature:
Schröttner H. : Die Elektronenmikroskopie in der Materialforschung / Electron Microscopy in Materials Research.

  • Fig. 1: Back-scattered electrons (RE) illustration for displaying material contrasts at electro-active ceramics
  • Fig. 2:  Back-scattered electrons (RE) illustration for displaying material contrasts at nickel base alloys
Back to list