Scanning transmission electron microscopy diffraction patterns

Optical microscopy (OM), polarized light microscopy (PLM), phase contrast microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) are the methods normally used for identification and quantification of the trace amounts of asbestos fibers that are encountered in the environment and lung tissue. Energy-dispersive X-ray spectrometry (EDXS) is used in both SEM and TEM for chemical analysis of individual particles, while selected-area electron diffraction (SAED) pattern analysis in TEM can provide details of the cell unit of individual particles of mass down to 10 g. It helps to differentiate between antigorite and chrysotile. Secondary ion mass spectrometry, laser microprobe mass spectrometry (EMMS), electron probe X-ray microanalysis (EPXMA), and X-ray photoelectron spectroscopy (XPS) are also analytical techniques used for asbestos chemical characterization. 

Analytical electron microscopy of individual catalyst particles provides much more information than just particle size and shape. The scanning transmission electron microscope (STEM) with analytical facilities allows chemical analysis and electron diffraction patterns to be obtained from areas on the order of lOnm in diameter. In this paper, examples of high spatial resolution chemical analysis by x-ray emission spectroscopy are drawn from supported Pd, bismuth and ferric molybdates, and ZSM-5 zeolite. 

With improvements in the preparation of more active HDS catalysts, MoS2 crystallites became smaller, and traditional physical techniques for characterization such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) became limited. In fact, today s best catalysts do not exhibit XRD patterns, and the active catalyst particles can no longer be observed directly by TEM. Thus, new techniques were required to provide structural information about Co(Ni)-Mo-S catalysts. As modern surface science characterization procedures evolved, they were immediately applied to the study of CoMoSx-based... 

The particle size and composition of the dispersed phase of the colloidal dispersions were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and photoluminescence (PL) spectroscopy. The TEM experiments were carried out on a LEO-906 device. The samples were obtained by placing a drop of the colloidal solution in toluene on TEM copper grid coated with a thin layer of carbon and evaporated in air at room temperature. XRD patterns of powders were obtained by a diffractometer HZG 4A using CuKa radiation. The UV-vis spectra of the colloidal dispersions were recorded using Cary 500 Scan UV-VIS-NIR spectrophotometer with a 1-cm quartz cell. The PL spectra were recorded using a SFL-1211A spectrofluorimeter. 

Fig. 11 a Scanning electron microscopy images, b WAXD profiles before and after partial enzymatic degradation, and c transmission electron microscopy image and electron diffraction pattern (inset) of P(3HB) nanofiber. (Reprinted with permission from Ishii et al. 2007. Copyright 2007, Elsevier B.V.)... 

Figure 10,2 Typical scanning electron microscopy (a,b) and transmission electron microscopy images (e,f) of synthetic and eggshell-derived calcium-deficient hydroxyapatite. Energy-dispersive X-ray spectra (c,d) and selected area electron diffraction pattern are shown in the inset.

Figure 8.14 (a) Scanning electron microscopy and (b) transmission electron microscopy images of Zr02 nanorods obtained via atomic layer deposition within AAO membranes (c) The electron diffraction pattern corroborates the high crystallinity of the obtained nanotubes [127], The scale bars correspond to lOOOnm (a) and lOOnm (b), respectively. Reproduced from Ref [127], with kind permission of the Royal Society of Chemistry. 

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