Surface structure studies

Crazing Incidence X-ray Methods for Near-surface Structural Studies... 

Sun SG, Cai WB, Wan LJ, Osawa M. 1999. Infrared absorption enhancement for CO adsorbed on Au films in perchloric acid solutions and effects of surface structure studied by cyclic voltammetry, scanning tunneling microscopy, and surface-enhanced IR spectroscopy. J Phys Chem B 103 2460-2466. 

The heterogeneous nature of polycrystalline solid electrodes invalidates the approximation of uniform surface or one-dimensional model used for the mercury electrode. Variations of pzc occur with surface structure. Study of single crystal sp metal electrodes has shown structural effects on adsorption [99]. 

Most surface structural studies combine results from several different surface science techniques applied to the same system. For an approach based on model calculations to be successful, it is necessary to construct reasonable structural models of surfaces. The application of techniques which cannot give explicit information on the arrangement of atoms in the near-surface region is often necessary to develop good surface structural models. 

Optical techniques are not limited to solid-vacuum interfaces like charged particle techniques, so their further development can expand the range of surface structural studies to solid-solid, solid-liquid, solid-gas and liquid-gas interfaces. 

Recently, surface structure studies have been aided by the development of scanning tunneling microscopy (STM) and atomic force microscopy (AFM). In STM, a very sharp metallic tip is brought into close proximity of a conducting sample through the use of piezoelectric scaimers (Figure 3). 

Spectral analysis, which is a standard technique for detection and quantification of orientation and/or periodicity of images, has been used for the characterization of pore orientation on gray level images [16]. This technique has been mainly applied to characterize the surface structure studied by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) [16]. This method is based on the calculation of the Fourier power spectra, defined in the frequency or k space, as S(k) = F( k) /1 k, where F(k)Fourier coefficients of the image. The... 

For surface structure studies, perhaps the most popular technique has been LEED (373). Elastically diffracted electrons from a monoenergetic beam directed to a single-crystal surface reveal structural properties of the surface that may differ from those of the bulk. Some applications of LEED to electrocatalyst characterization were cited in Section IV (106,148,386). Other, less specific, but valuable surface examination techniques, such as scanning electron microscopy (SEM) and X-ray microprobe analysis, have not been used in electrocatalytic studies. They could provide information on surface changes caused by reaction, some of which may lead to catalyst deactivation (256,257). Since these techniques use an electron beam, they can be coupled with previously discussed methods (e.g. AES or XPS) to obtain a qualitative mapping of the structure and composition of a catalytic surface. 

Surface diffraction Surface structural studies Undulator... 

We will treat this system in some detail because it represents an excellent example of how the combination of kinetic measurements, photoemission, electron spectroscopic and surface structure studies in conjunction with theoretical calculations can produce a rather complete understanding of an adsorption process. However, the work has effectively been restricted to 110 surfaces for two reasons. Firstly, from an experimental viewpoint, it is the surface obtained by in situ cleavage and, until very recently, with the advent of molecular beam epitaxy [111], there was no alternative technique for preparing clean, damage-free surfaces. From a theoretical... 

Small organic molecules have been the subject of most surface-structure studies of molecular adsorbates. Most of these molecules are alkenes (such as ethylene) and aromatic molecules (such as benzene and substituted benzenes). Saturated hydrocarbons physisorb only at low temperatures and although some ordered surface structures have been obtained using graphite as a substrate, these structures exhibit van der Waals packing without forming stronger chemical bonds. 

A. Ihs, Ph.D. Thesis, Organic Molecules on Metal Surfaces Structural Studies Using Infrared and X-ray Photoelectron Spectroscopy, Linkoping University, Linkoping, 1993. 

Iwahashi, T., Nishi, T., Yamane, H., Miyamae, T., Kanai, K., Seki, K., Kim, D. and Ouchi, Y, Surface structural study on ionic liquids using metastable atom electron spectroscopy, J. Phys. Chem. C113,19237-19243 (2009). 

C. Woll, R.J. Wilson, S. Chiang, H.C. Zeng, K.A.R. Mitchell, Oxygen on Cu(lOO) surface-structure studied by scanning tunneling microscopy and by LEED multiple-scattering calculations. Phys. Rev. B 42(18), 11926-11929 (1990)... 

N Lee, A Badzian. H-plasma annealed and homoepitaxiaUy grown diamond (001) surface structure studies with RHEED. Phys Rev B, 53 R1744, 1996. 

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