Electron microscopy, high-resolution transmission

The optical treatment in Chapter 1 is concerned with the nature of the image of a simple two-dimensional grid formed by a perfect lens, in focus, using monochromatic light. However, to understand the nature of the lattice image formed in the electron microscope, we must take into account the thickness and the orientation of the three-dimensional crystal, the defect of focus and the aberrations of the objective lens (see Chapter 2), and the beam convergence, because all these factors influence the relative phases of the diffracted beams that are permitted to pass through the objective aperture. 

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The spatial arrangement of atoms in two-dimensional protein arrays can be detennined using high-resolution transmission electron microscopy [20]. The measurements have to be carried out in high vacuum, but since tire metliod is used above all for investigating membrane proteins, it may be supposed tliat tire presence of tire lipid bilayer ensures tliat tire protein remains essentially in its native configuration. 

Figure 6 High-resolution transmission electron microscopy image of an epitaxial thin film of Y Ba2Cu307 j, grown on LaAI03, shown in cross section. (Courtesy of T. E. MKchell, Los Alamos National Laboratory)...

High Resolution Transmission Electron Microscopy and Associated Techniques. (P. R. Buseck, J. M. Cowley, and L. Eyring, eds.) Oxford University Press, New York, 1988. A review covering these techniques in detail (except X-ray microanalysis) including extensive material on high-resolution TEM. 

Transmission Electron Microscopy Transmission Electron Microscope Conventional Transmission Electron Microscopy Scannir Transmission Electron Microscopy High Resolution Transmission Electron Microscopy Selected Area Diffraction Analytical Elearon Microscopy Convergent Beam Elearon DifFraaion Lorentz Transmission Electron Microscopy... 

Regarding a historical perspective on carbon nanotubes, very small diameter (less than 10 nm) carbon filaments were observed in the 1970 s through synthesis of vapor grown carbon fibers prepared by the decomposition of benzene at 1100°C in the presence of Fe catalyst particles of 10 nm diameter [11, 12]. However, no detailed systematic studies of such very thin filaments were reported in these early years, and it was not until lijima s observation of carbon nanotubes by high resolution transmission electron microscopy (HRTEM) that the carbon nanotube field was seriously launched. A direct stimulus to the systematic study of carbon filaments of very small diameters came from the discovery of fullerenes by Kroto, Smalley, and coworkers [1], The realization that the terminations of the carbon nanotubes were fullerene-like caps or hemispheres explained why the smallest diameter carbon nanotube observed would be the same as the diameter of the Ceo molecule, though theoretical predictions suggest that nanotubes arc more stable than fullerenes of the same radius [13]. The lijima observation heralded the entry of many scientists into the field of carbon nanotubes, stimulated especially by the un-... 

The earliest observations of carbon nanotubes with very small (nanometer) diameters [151, 158, 159] are shown in Fig. 14. Here we see results of high resolution transmission electron microscopy (TEM) measurements, providing evidence for m-long multi-layer carbon nanotubes, with cross-sections showing several concentric coaxial nanotubes and a hollow core. One nanotube has... 

Oshida, K., Kogiso, K., Matsubayashi, K., Takeuchi, K., Kobayashi, S., Endo, M., Dressclhaus, M. S., Drcsselhaus, G., Analysis of pore structure of activated carbon fibers using high resolution transmission electron microscopy and image processing, 7. Mater. Res., 1995, 10(10), 2507 2517. 

High-resolution transmission electron microscopy (HREM) is the technique best suited for the structural characterization of nanometer-sized graphitic particles. In-situ processing of fullerene-related structures may be performed, and it has been shown that carbonaceous materials transform themselves into quasi-spherical onion-like graphitic particles under the effect of intense electron irradiation[l 1],... 

The length and the diameter of MWCNT can be measured directly by TEM. From high-resolution transmission electron microscopy (HRTEM) images exhibiting oo.l fringes follows the number of coaxial tubes and possibly the microstructure of the caps in MWCNT, as viewed along the incident electron beam [24], Also anomalous intercylinder spacings and defects are revealed in this way [1,11]. 

However, in more recent times science has made rapid strides in this direction. It is now possible to use EXAFS in situ during a catalytic reaction to examine the average coordination of metal atoms in the small particles which often exist in precious metal catalysts [2]. High resolution transmission electron microscopy has evolved to the level of atomic resolution, but can only be used ex-situ, or in situ with moderate pressures when special cells are fitted [3]. 

Crystalline phases (truncated octahedra) of 5 nm silver particles, thiolate protected as well, have been detected by means of high-resolution transmission electron microscopy (HRTEM) [26-28]. Three-dimensional architectures of 5-6 nm thiolate-stabilized gold particles have also been described [29]. Several other reports on 3D superlattices of metal nanoparticles have become known during the last few years [30-33]. 

Ag-core/Au-shell bimetallic nanoparticles were prepared by NaBH4 reduction method [124]. UV-Vis spectra were recorded and compared with various ratios of AuAg alloy nanoparticles. The UV-Vis spectra of bimetallic nanoparticles suggested the formation of core/shell structure. Furthermore, the high-resolution transmission electron microscopy (HRTEM) image of the nanoparticles confirmed the core/shell type configuration directly. 

P. Buseck, J. M. Cowley, L. Eyring, High Resolution Transmission Electron Microscopy and Related Techniques, Oxford University Press, Oxford, 1989. 

S. Horiuchi, Fundamentals of High-Resolution Transmission Electron Microscopy, North-Holland, Amsterdam, 1994. 

The synthesis of nanoparticles using plant biomass has been investigated by many [24,26]. Using high resolution transmission electron microscopy (HRTEM), it has been... 

Figure 15.1 High resolution transmission electron microscopy images (HR-TEM) of 5 wt% Pd (a) and 50 wt% Pt-Ru (b) particles supported on carbon supports of the Sibunit family with surface areas of about 6m g (a) and 72m g (b). (c) Fourier-transformed image of (b). ((a) Reprinted from Pronkin et al. [2007], Copyright 2007, with permission from Elsevier, (b) and (c) reprinted from Gavrilov et al. [2007]—Reproduced by permission of the PCCP Owner Societies.)...

High Resolution Transmission Electron Microscopy (HRTEM, Philips CM20, 200 kV) was applied to get structural and nanotextural information on the fibers, by imaging the profile of the aromatic carbon layers in the 002-lattice fringe mode. A carbon fiber coated with pyrolytic carbon was incorporated in epoxy resin and a transverse section obtained by ultramicrotomy was deposited on a holey carbon film. An in-house made image analysis procedure was used to get quantitative data on the composite. 

The contribution by Rouzaud et al. teaches to apply a modified version of high resolution Transmission Electron Microscopy (TEM) as an efficient technique of quantitative investigation of the mechanism of irreversible capacity loss in various carbon candidates for application in lithium-ion batteries. The authors introduce the Corridor model , which is interesting and is likely to stimulate active discussion within the lithium-ion battery community. Besides carbon fibers coated with polycarbon (a candidate anode material for lithium-ion technology), authors study carbon aerogels, a known material for supercapacitor application. Besides the capability to form an efficient double electric layer in these aerogels, authors... 

HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY IMAGE ANALYSIS OF DISORDERED CARBONS USED FOR ELECTROCHEMICAL STORAGE OF ENERGY... 

Rouzaud J.N. and Clinard C. Quantitative high-resolution transmission electron microscopy a promising tool for carbon materials characterization. Fuel Proces. Technol. 2002 77-78 229-35. 

High resolution transmission electron microscopy (HRTEM) micrographies were performed with a JEOL JEM-3010 microscope operating at 300 kV (Cs= 0.6 mm, point resolution 1.7 A). Images were recorded with CCD camera (MultiScan model 794, Gatan, 1024 x 1024 pixels, pixel size 24 x 24 pm2). The powder samples were mixed in ethanol and then ultrasonicated for 10 min. A drop of the wet sample was placed on a copper grid and then allowed to dry for 10 min before TEM analysis. 

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