Lattice imaging

A progressive etching technique (39,40), combined with x-ray diffraction analysis, revealed the presence of a number of a polytypes within a single crystal of sihcon carbide. Work using lattice imaging techniques via transmission electron microscopy has shown that a-siUcon carbide formed by transformation from the P-phase (cubic) can consist of a number of the a polytypes in a syntactic array (41). 

In Fig. 13 is shown the 002 lattice images of an as-formed very thin VGCF. The innermost core diameter (ca. 20 nm as indicated by arrows) has two layers it is rather straight and appears to be the primary nanotube. The outer carbon layers, with diameters ca. 3-4 nm, are quite uniformly stacked parallel to the central core with 0.35 nm spacing. From the difference in structure as well as the special features in the mechanical strength (as in Fig. 7) it might appear possible that the two intrinsically different types of material... 

Fig. 13. HRTEM image of an as-grown thick PCNT. 002 lattice image demonstrates the innermost hollow core (core diam. 2.13 nm) presumably corresponding to the as-formed nanotube. The straight and continuous innermost two fringes similar to Fig. 5 are seen (arrow).

Fig. 10. Analysis of the atomic lattice images of the lead compound entering CNTs by capillary forces (a)detailed view of the high resolution image of the filling material, (b)tetragonal PbO atomic arrangement, note the layered structure and (c)tetragonal PbO observed in the [111] direction, note that the distribution of lead atoms follows the contrast pattern observable in (a), (d)bidimensional projection of the deduced PbO filling orientation inside CNTs as viewed in the tube axis direction, note that PbO layers are parallel to the cylindrical CNT cavity.

Fig. 4 Oxygen Is XPS spectra including curve-fitted components for (a) Catalyst I, (b) Catalyst I after reduction In Fig. 2, a marble-like pattern was observed, which is attributable to solid solution phase of CoO and MgO, because XRD measurement on Catalyst II showed the existence of CoO-MgO solid solution phase [7, 8]. On the other hand, for Catalyst I, no solid solution phase of CoO-MgO was observed. In addition, XRD pattern of Catalyst I indicated the existence of CoO or C03O4. These results suggest that in the case of Catalyst I, Co is loaded on the surface of MgO as CoO or C03O4 phase. Magnified TEM image of Catalyst I after reduction is shown in Fig. 3. In this figure, crystalline lattice image was observed. It is likely that the observed lattice corresponds to the metal phase of Co, because XRD measurement on Catalyst I after reduction showed the existence of Co metal phase [7, 8].

High-resolution lattice images (e.g., Fig. 8(c)) reveal that the platelets are associated neither with dislocation loops nor with either intrinsic or extrinsic stacking faults. The platelets appear to be microcracks in which the separation between adjacent planes of Si atoms over a finite area is increased due to the slight displacement of these atoms from their substitutional lattice sites. From computer simulations, the lattice images are... 

Not every molecular crystal can be resolved at 3A resolution, especially not ones built of aliphatic nonconjugated molecules, which have lower electron densities and are more subject to radiation damage. The final aim of obtaining a direct three-dimensional picture of the chiral molecule itself thus cannot yet be pursued. Assignment of absolute configuration by lattice imaging, however, may be achieved even at lower resolutions (129). 

Fig. 11.2 (a) HAADF-STEM image of a stained cell section (40nm thick). A SWNT cluster within a lysosome invading the lysosomal cell membrane, (b) Corresponding high-resolution lattice image of SWNTs at the lysosomal membrane from boxed area. Cytoplasm (cy) and secondary... 

Fig. 17.2 Structural and morphological characterization of W03/CNT sheets prepared at 300 °C and 400 °C (a), (d) SEM images showing the morphology of W03/CNT sheets (b), (e) TEM images showing the W03 wrapping on the CNT surface (c), (f) HRTEM images showing the lattice images of W03. Reprinted with permission from [20], Copyright 2012, The Royal Society of Chemistry.

Figure 1. CTF and simulated lattice images of Si3N4[0001 ] for selected microscopes and focus values. Stmctural models are superimposed.

Figure 4. The filtered lattice images from the grain boundary GB region obtained with...

Figure 5. Filtered lattice images of the overlapping layers L obtained with particular diffraction spots from FT of Fig. 5(j) (a) 1 - (440)Y2O3,

Fig. 2.4 Chrysotile asbestos sectioned perpendicular to the fiber axis. Electron micrograph showing typical lattice images of the layers of this serpentine mineral rolled into hollow cylinders (fibrils).

Submicrofibril and triple-stranded left-hand helical microfibrils are found in tobacco primary cell wall and bacterial A. xylinum cellulose. We suspect from our results and the literature survey outlined in reference (1) that the triple stranded structures are prominent in the primary plant cell wall. The highly crystalline cellulose of plant and algae secondary cell wall appears by X-ray fiber diffraction (18,19) and TEM lattice imaging (20-23) to be largely crystalline arrays of planar straight chains of (l-4)-/3-D-glucan chains. 

Fig. 4.18 H RTEM of 6-line ferrihydrite with lattice images showing its crystalline nature (Janney et al. 2000a, with permission courtesy D. E. Janney).

Fig. 17.2 Left A schematic picture of ferritin. (Mann, 1986, with permission ). Right Lattice image of a singie domain offerrihy-drite from the inorganic core of a human ferritin moiecuie. The fringes of ca. 0.27 nm correspond to the (110) piane (bar is 2 nm) (courtesy S. Mann).

---