BSE images

In secondary electron microscopy (SEM), in most cases, SEs are used for imaging. BSE detectors are closely connected with element analysis of the specimen. Other types are more or less seldom used in electron microscopy. In transmission electron microscopy (TEM), TEs will be processed to give an image. 

Scrivener (1988) studied the Aspdin paste with backscattered electron imaging (BSE), showing clearly the development of hydration products pseudomor-phic after the original clinker crystals and drawing attention to the occurrence of layers of hydration product ( inner product ). 

Figure 4.11 SEM image (BSE mode) overview of axial section of biomorphous SiSiC ceramics prepared from beech wood-derived biocarbon templates by LSI processing. The infiltration/reaction time was 60min at 1550°C. After Ref [354].

Direct Porosity Back scatter electron imaging (BSE), energy dispersive x-ray analysis (EDXA)... 

Figure 1. SEM-images (BSE) of carbonized MCC spheres loaded with Fe(N03)3 9H20, pyrolyzed at 500°C (left) and 800°C (right). Scale bars 100 pm.

Figure 5. SEM-images (BSE) of MCC-spheres loaded with Cu(N03)2-2.5H20 and pyrolyzed at 800°C at different magnifications. Scale bar left 50 pm and right 5 pm.

Figure 10 displays a SEM-image (BSE) of CS impregnated with Ni(N03)2 6H20 pyrolyzed at 800°C. Finely divided nickel particles have formed onto the surface of the CS spheres. 

One further breaks down the secondary electron contributions into three groups SEI, SEII and SEIII. SEIs result from the interaction of the incident beam with the sample at the point of entry. SEIIs are produced by BSE s on exiting the sample. SEIIIs are produced by BSEs which have exited the surface of the sample and further interact with components on the interior of the SEM usually not related to the sample. SEIIs and SEIIIs come from regions far outside that defined by the incident probe and can cause serious degradation of the resolution of the image. 

Figure 9.12 Schematic diagram illustrating the geometry of detectors used for STEM BF, STEM HAADF and STM BSE imaging. (Reproduced from Ref. 35).

Figure 9.13 (a) SEM BSE image and (b) STEM HAADF image of Pd nanoparticles on a carbon support. The clarity of the images illustrates the advantage of the HAADF and BSE approach. (Reproduced from Ref. 36). 

I. Digital X-ray Mapping. The beam may be controlled by a computer to move within a grid of points on the specimen surface. The beam remains at each point for a pre-set time while an analysis is carried out. With an EDS system, data from several elements may be collected at the same time and a BSE image may also be acquired in the same experiment. Digital X-ray maps may then be displayed for each of the chosen elements in turn. 

Figure 11 Raman (left) and ESEM (right, SE and BSE) images (for explanation see text). (See Color Plate Section at the end of this book.)...

Four samples were similarly selected for the EPMA experiments. The samples were dried and embedded in polished epoxy cylindrical plugs. Backscattered electron (BSE) images as well as elemental maps of As, Fe and Ni (EDS/WDS) were collected using a JEOL 8600 Superprobe electron microprobe analyzer (Dept, of Geological Sciences, University of Saskatchewan). 

Fig. 4. BSE image of mine tailings showing the presence of gypsum nodules with bright rims around them.

Typical examples of Rutherford-scattered imaging of nanoparticles of a commercially important Pd/C catalyst recorded with (a) a BSE detector in a field emission scanning electron microscope as well as (b) a STEM HAADF image of the same 5% Pd/C sample, recorded in the same instrument, are shown... 

The examples shown in the preceding paragraphs illustrate that combined use of HAADF imaging and BSE imaging, both using Rutherford-scattered electrons,... 

Fig. 2. SEM-BSE image and EPMA maps from Esfordi deposit, a) White crystals in fractures are REE minerals, b). RE minerals (sketched by black colour) are interstitial to actinolite (gray parts), c) RE minerals (black) and apatite (white) EPMA map.

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