The transmission electron microscope

To illustrate the effect of radial release interactions on the structure/ property relationships in shock-loaded materials, experiments were conducted on copper shock loaded using several shock-recovery designs that yielded differences in es but all having been subjected to a 10 GPa, 1 fis pulse duration, shock process [13]. Compression specimens were sectioned from these soft recovery samples to measure the reload yield behavior, and examined in the transmission electron microscope (TEM) to study the substructure evolution. The substructure and yield strength of the bulk shock-loaded copper samples were found to depend on the amount of e, in the shock-recovered sample at a constant peak pressure and pulse duration. In Fig. 6.8 the quasi-static reload yield strength of the 10 GPa shock-loaded copper is observed to increase with increasing residual sample strain. 

Electron Energy-Loss Spectroscopy in the Transmission Electron Microscope (EELS)... 

For the purpose of a detailed materials characterization, the optical microscope has been supplanted by two more potent instruments the Transmission Electron Microscope (TEM) and the Scanning Electron Microscope (SEM). Because of its reasonable cost and the wide range of information that it provides in a timely manner, the SEM often replaces the optical microscope as the preferred starting tool for materials studies. 

Historically, EELS is one of the oldest spectroscopic techniques based ancillary to the transmission electron microscope. In the early 1940s the principle of atomic level excitation for light element detection capability was demonstrated by using EELS to measure C, N, and O. Unfortunately, at that time the instruments were limited by detection capabilities (film) and extremely poor vacuum levels, which caused severe contamination of the specimens. Twenty-five years later the experimental technique was revived with the advent of modern instrumentation. The basis for quantification and its development as an analytical tool followed in the mid 1970s. Recent reviews can be found in the works by Joy, Maher and Silcox " Colliex and the excellent books by Raether and Egerton. ... 

In electron-optical instruments, e.g. the scanning electron microscope (SEM), the electron-probe microanalyzer (EPMA), and the transmission electron microscope there is always a wealth of signals, caused by the interaction between the primary electrons and the target, which can be used for materials characterization via imaging, diffraction, and chemical analysis. The different interaction processes for an electron-transparent crystalline specimen inside a TEM are sketched in Eig. 2.31. 

As an indication of the changes in deformation modes that can be produced in ionomers by increase of ion content, consider poly(styrene-co-sodium methacrylate). In ionomers of low ion content, the only observed deformation mode in strained thin films cast from tetra hydrofuran (THF), a nonpolar solvent, is localized crazing. But for ion contents near to or above the critical value of about 6 mol%, both crazing and shear deformation bands have been observed. This is demonstrated in the transmission electron microscope (TEM) scan of Fig. 3 for an ionomer of 8.2 mol% ion content. Somewhat similar deformation patterns have also been observed in a Na-SPS ionomer having an ion content of 7.5 mol%. Clearly, in both of these ionomers, the presence of a... 

FIGURE 3.12 Morphology of mbber-silica hybrid composites synthesized from solution process using different solvents (a) and (b) are the scanning electron microscopic (SEM) pictures of acrylic rubber (ACM)-silica hybrid composites prepared from THF (T) and ethyl acetate (EAc) (E) and (c) and (d) are the transmission electron microscopic (TEM) pictures of epoxidized natural rubber (ENR)-siUca hybrid composites synthesized from THF and chloroform (CH). (From Bandyopadhyay, A., De Sarkar, M., and Bhowmick, A.K., J. Appl. Polym. Sci., 95, 1418, 2005 and Bandyopadhyay, A., De Sarkar, M., and Bhowmick, A.K., J. Mater. Sci., 40, 53, 2005. Courtesy of Wiley InterScience and Springer, respectively.)... 

Frank, J., Electron Tomography—Three-dimensional Imaging with the Transmission Electron Microscope, Plenum Press, New York, 1992. 

Griffin RL. Using the Transmission Electron Microscope in the Biological Sciences, Ellis Horwood, New York, 1990. 

The transmission electron microscope is now well established as a useful tool for the characterization of supported heterogeneous catalysts(l). Axial bright-field imaging in the conventional transmission electron microscope (CTEM) is routinely used to provide the catalyst chemist with details concerning particle size distributions, 3), particle disposition over the support material(2-6) as well as particle morphology(7). Internal crystal structure(8-10), and elemental compositions(ll) may be inferred by direct structure imaging. 

Even under magnifications of the order of 105, micro PS looks rather homogeneous under the transmission electron microscope, as shown in Fig. 7.2a. This is in contrast to the microstructure of meso PS, which can be revealed at this magnification, as shown in Fig. 7.2 b. It requires HREM techniques to reveal the struc-... 

Local composition is very useful supplementary information that can be obtained in many of the transmission electron microscopes (TEM). The two main methods to measure local composition are electron energy loss spectrometry (EELS), which is a topic of a separate paper in this volume (Mayer 2004) and x-ray emission spectrometry, which is named EDS or EDX after the energy dispersive spectrometer, because this type of x-ray detection became ubiquitous in the TEM. Present paper introduces this latter method, which measures the X-rays produced by the fast electrons of the TEM, bombarding the sample, to determine the local composition. As an independent topic, information content and usage of the popular X-ray powder dififaction database is also introduced here. Combination of information from these two sources results in an efficient phase identification. Identification of known phases is contrasted to solving unknown stmctures, the latter being the topic of the largest fiaction of this school. 

The coating with platinum under an angle of 45° illuminates the differences in contrast because platinum precipitation takes place preferably at sample positions facing the platinum source in luff, whereas sample positions in lee are less coated or not at all. In the transmission electron microscope (TEM), these different thicknesses of platinum absorb the electron beam differently, thus providing the formation of shadows. This phenomenon produces the plastic impression of the transmission electron micrographs. 

Ultrastructural examination of duckweed frond (Fig. 5) and root tissues treated with 18 (100 xM) revealed membrane damage to the tonoplast after 12 hours of exposure. The samples viewed through the transmission electron microscope showed ruptured tonoplasts, free-floating organelles and loss of cytoplasm relative to control tissues. The tonoplast may be the primary target for the phytotoxic effect of 18, which represents an unusual, if not unique, toxic mechanism among phytotoxic agents. 

X 1) to (1 X 5) surface reconstructions of the (Oil) and (001) surfaces of fee metals such as Au, Pt and Ir have also been successfully studied with the STM,19,20 with the transmission electron microscope (TEM)13,21 and with the field ion microscope.14,15,22 Some of the FIM surface atomic reconstruction studies will be described below. 

Advances in techniques for handling and analyzing very small particles have allowed detailed examination and characterization of IDPs. Especially useful instruments include the transmission electron microscope ( ), synchrotron facilities, and the ion microprobe. 

Modem instmments use all of these signals to extract information about a sample. These include the scanning electron microscope, the transmission electron microscope, the electron microprobe, and the auger nanoprobe. For many of these techniques, a conductive... 

View the grid at x 125,000 with the transmission electron microscope. Electro-nmicrographs should be taken and scanned into either a monochrome or full-color image analyzer for morphometric analysis. It is also possible to attach the image analysis system directly to the electron microscope and so eliminate... 

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