BSE-SEM

Fig. 22a-c BSE-SEM images of crack-tip microdeformation in iPP containing approximately 80 wt% ji phase tested at 0.001 m s 1 and 25 °C. a Overview of the crack-tip damage zone, b and c details from the periphery of the damage zone. The arrows indicate the loading direction [24]... 

Application High-resolution signal (TEM, STEM) Back-scattering of electrons (BSE signal in SEM) Analytical signal (TEM, STEM, SEM) Emission of secondary electrons (SE signal in SEM)... 

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 9.13 (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). 

Fig. 2.55 Scanning electron micrographs (SEM) in the back scattered electron (BSE) mode at 100,000x of the ABCR MgH + 5 wt.% n-Ni mixtures ball- S milled powder under 700 kPa hydrogen with varying SSA (see the insets in the pictures)...

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.

Fig. 2. SEM-BSE images of phosphate minerals in massive sulfides, (a) detrital monazite grain with a metamorphic rim, (b) detrital zircon grain with a xenotime rim, (o) complex zonation of a xenotime mass, and (d) apatite mass with a syntaxial overgrowth...

Fig. 5. SEM-BSE image showing Au, eiectrum, native Bi and BiTe aiioys precipitated in an anneaied amphiboiite-facies metabasait iayer. The inset CL image reveais aiioys and suifides in contact with new generations of quartz (red) and piagiociase (dark) that records dissoiution-precipitation reactions isoiated aiong the grain boundaries of a previous anneaied matrix.

Fig. 4. Photomicrograph of a SEM-BSE image showing arsenopyrite enoiosed in a serrated pyrite porphyrobiast from the Key Anaoon Main zone. Note The euhedrai and serrated pyrite oontain inoiusions of sphaierite and pyrrhotite (DDH KA64-712.8 m).

The use of BSE images on the SEM screen was ideal for the detection of minerals in low rank coals. The difference in atomic number between the major components of the coal matrix (C, H, N and 0) and the elements present in the mineral species (Si, Al, Fe, Ca) causes the minerals to appear bright against the dark coal background Variations in the BSE brightness between minerals was such that the different minerals present were also distinguishable. However, it is difficult to differentiate between quartz and clay (kaolinite) just from a BSE image. 

XRD allows the determination of the actual mineral species present. The bulk coal samples resulted in an x-ray pattern with a high background due to the coal matrix. The major mineral species were easily determined, however the minor species could not be detected. As with the SEM-BSE analysis, interpretation of results in a quantitative manner (in relation to the coal) is difficult. The major minerals detected were quartz, kaolinite, gypsum and marcasite. 

MPa (A) backscatter (BSE) micrograph differentiation of the alloy into in its compounds (here Bismuth and Cadmium), (B) SEM (secondary electron microscopy) micrograph WM... 

A conventional SEM (backscattered electrons) micrograph of a Ni-Al203 nanocomposite demonstrating problematic use of the BSE signal for microstructure characterization. 

SEM micrographs of Vickers indentation-induced damage in material SiC-S (peak load 10 kg) (a) SE image, (b) and (c) BSE images. 

SEs and BSEs are typically detected by an Everhart-Thornley (ET) scintillator-photomultiplier secondary electron detector. The SEM image is shaped on a cathode ray tube screen, whose electron beam is scanned synchronously with the high-energy electron beam, so that an image of the surface of the specimen is formed [52], The quality of this SEM image is directly related to the intensity of the secondary and/or BSE emission detected at each x- and y-point throughout the scanning of the electron beam across the surface of the material [8],... 

Scanning electron micrographs (SEM) were obtained using a JSM 5500 LV (Jeol, Japan) electron microscope. The observations were performed in a secondary electron (SE) and in a backscattering electron (BSE) mode at a low vacuum pressure of 12 kPa. 

Electron microprobes permit chemical microanalysis as well as SEM and BSE detection, often referred to as analytical electron microscopy (AEM), or electron probe microanalysis (EPMA)56 57. This is because another product of the surface interaction with an incident electron beam is X-ray photons which have wavelengths and energies dependent on element identity and on the electron shell causing the emission. Analysis of these photons can give a local chemical analysis of the surface. Resolution of 1 pm is attainable. Two types of X-ray spectrometer can be employed ... 

The resolution of SEMs is now suitable for nano-materials characterization. High resolution SEM is a powerful instrument for imaging fine structures of materials and nanoparticles fabricated by nanotechnology. In lens SE, BSE modes, and STEM mode are often performed to check the structure of CNT growths or CNT as delivered by commercial producers, and sometimes coupled with TEM. Even the single-walled carbon nanotubes can easily be observed by HR-SEM (see Figure 3.13). The STEM mode can also be used for free CNT observation (75). 

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