HAADF dark field

The HAADF dark field detector operated with a 60 [mrad] inner radius detects electrons that are for the most part scattered as a result of thermal and direct atomic scattering events with the elastically scattered difhaction electrons passing through the inner hole in the detector. The intensities in the dark field image produced can be interpreted directly in terms of the atomic species present and relative concentrations of differing atomic species. Intensity changes can also be interpreted in terms of sample thickness. ... 

Fig. 12. Schematic of the information from HRSTEM, DF, and high-angle annular dark-field (HAADF) microscopy.

Fig. 7.6 Scheme of a scanning transmission electron microscope with bright- and dark-field detectors. ADF annular dark field HAADF high-angle annular dark field. (Adapted from [7]). 

HAADF high-angle annular dark field... 

Alternatively, images can be formed with electrons scattered at high angles (HAADF mode, for High Angle Annular Dark Field mode). An annular detector is placed below the sample and the focused electron beam is scanned over the sample. Interestingly, the contrast is not altered by diffraction phenomena and depends both the thickness and the composition (25). 

Fig. 10. a Bright-field (BF) images of mesoporous silica with Pd Ru particles, b HAADF (high-angle annular dark field) images of mesoporous sihca with Pd Ru particles. c,d Electron-stimulated X-ray emission images prove that particles are intact. Reprinted with permission from [74]. Copyright (2001) American Chemical Society... 

This chapter includes a review of the recent literature on polymer microscopy. The basic principles and current challenges of the techniques, as well as the experimental aspects of sample preparation and observation are reviewed elsewhere [1-8]. Specific techniques are surveyed in other reviews for instance TEM [9], SEM [10], Field emission SEM [11], and high angle annular dark field (HAADF)-STEM [12]. 

HAADF High angle angular dark field (imaging in TEM)... 

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