Abstract : In Scanning Electron Microscope (SEM), Electron Channeling Contrast Imaging (ECCI) is an attractive technique that allows direct observations of crystalline defects on bulk samples, thin films or substrates [1-4]. ECCI takes advantage from the strong dependence between the backscattred electrons intensity and the crystal orientation relative to the incident electron beam.
Defects, such as dislocations, can be imaged with a visibility of depth below the surface of about a hundred nanometers (the same order of magnitude of the thickness of a TEM thin foil or a thin layer deposited on a substrate). It has been shown that the channeling contrast generated by these linear defects is influenced by the modification of diffraction conditions caused by the lattice distortions around their core [5,6].
In this work, fundamental and experimental aspects of electron diffraction for characterizing dislocation by ECCI are reported. Interpretation of contrast in (g,-g) and its evolution along a Kikuchi band are given. Experimentally, the potentiality of the technique ECCI is explored on several dislocation configurations in grained Interstitial-Free (IF) steel (Fe − 1 %Si) where a dislocation dipole is observed and fully characterized for the first time in SEM [5].
References
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[6] H. Kriaa, A. Guitton, N. Maloufi, Materials 18, 2019