Atomic resolution imaging

In Fig. 4 we show an atomic resolution image of a carbon tube. The structure imaged at the upper right corner of the picture comes from another tube. Both of them were —1000 A long. A perfect honeycomb surface structure is observed. By taking into account the curvature of the tube surface and the STM imaging profile, we find the same lattice parameter as that of. graphite (1.42 A). This directly proves that the tubu-... 

The experiments were carried out in ambient air.78 79 STM images were obtained at 300 K following current, I, or potential, Uwr, application in ambient air at 550 K. Figure 5.49 shows an unfiltered atomic resolution image of the Pt (111) surface after assembling the solid electrolyte cell before any current or potential application. 

Figure 4.18 (a) STM image (39 x 23 nm) 02 molecules at Ag(l 10) at 65 K, illustrating the hot precursor mechanism at a coverage of 0.02. The inset shows an atomic resolution image of the silver surface and the 02 molecules as dark holes. Also shown (b) is a ball model with oxygen molecules (black) and surface silver atoms (white) and second layer silver atoms (grey). (Reproduced from Ref. 32). 

Yields atomic resolution images of surface in real space surfaces... 

It is interesting to note that none of the STM work on metal surfaces (i.e., Pt and Al) discussed above yielded images with atomic resolution. In fact, although atomic resolution images of... 

One of the most significant applications of STM to electrochemistry would involve the application of the full spectroscopic and imaging powers of the STM for electrode surfaces in contact with electrolytes. Such operation should enable the electrochemist to access, for the first time, a host of analytical techniques in a relatively simple and straightforward manner. It seems reasonable to expect at this time that atomic resolution images, I-V spectra, and work function maps should all be obtainable in aqueous and nonaqueous electrochemical environments. Moreover, the evolution of such information as a function of time will yield new knowledge about key electrochemical processes. The current state of STM applications to electrochemistry is discussed below. 

FIGURE 10.1 (a) Lower magnification TEM images of ITO thin film on polyester substrate in cross-sectional view, (b) atomic-resolution image of ITO film near the surface showing the crystalline feature. 

Atom resolution images can be obtained in particles with diameter down to 100 A. This technique can be extremely important in particle characterization. However in order to obtain usefull information from atomic images, computer calculations are required for proper image interpretation. 

Fig. 16.5. Atomic structure of the U connection on Au(lll). (a) Model of the atomic structure open circles, atoms of the second layer shaded circles, atoms of the top layer (dark, fee domain light, transition region medium, hep region). The dark line marks a cut along the surface atoms passing through two transition regions. This line and thus the surface atoms arc rotated by 2° relative to the bulk lattice, (b) Atomic-resolution image of the U connections. The lines correspond to the line in the model. (Reproduced from Barth et al., 1990, with permission.)...

Wintterlin, J., Wiechers, J., Brune, H., Giitsch, T., Hofer, H., and Behm, R. J. (1989). Atomic-resolution imaging of close-packed metal surfaces by scanning tunneling microscopy. Phys. Rev. Lett. 62, 59-62. 

A new development in powerful EE STEM/TEM by Boyes et al (2001), called 2-2-2 200 kV held emission STEM/TEM, is now becoming available which combines atomic-resolution imaging with atomic level chemical and crystallographic analyses with 2 A (0.2 nm) resoluhon in each of the TEM, STEM and chemical analysis modes (hence 2-2-2), providing new oppormnihes in catalysis. In the 2-2-2 EESTEM, the incoherent HAADE-STEM provides... 

Schardt, B.C., Yau. Shneh-Lin, and F. Rinaldi Atomic Resolution Imaging of Adsorbates on Metal Surfaces in Air Iodine Adsorption on Pt(III), Science, 1050... 

One might think that it is difficult to produce tips which allow atomic resolution imaging. This is fortunately not the case. Often a wire made of Pt/Ir which is just cut with scissors produces atomically resolved images. Some researchers further etch the tip to get more reproducible results. 

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