Surfaces, studies

A tremendous amount of work has been done to delineate the detailed reaction mechanisms for many catalytic reactions on well characterized surfaces [1, 45]. Many of tiiese studies involved impinging molecules onto surfaces at relatively low pressures, and then interrogating the surfaces in vacuum with surface science teclmiques. For example, a usefiil technique for catalytic studies is TPD, as the reactants can be adsorbed onto the sample in one step, and the products fonned in a second step when the sample is heated. Note that catalytic surface studies have also been perfonned by reacting samples in a high-pressure cell, and then returning them to vacuum for measurement. 

Wu M-C, Estrada C A, Corneille J S and Goodman D W 1996 Model surface studies of metal oxides adsorption of water and methanol on ultrathin MgO films on Mo(IOO) J. Chem. Phys. 96 3892... 

Zong Q, inniss D, K]oiier K and Eiings V B 1993 Fractured poiymer/siiica fiber surface studied by tapping mode atomic force microscopy Surf. Sc/. Lett. 290 L688... 

Figure Bl.21.1 shows a number of other clean umeconstnicted low-Miller-index surfaces. Most surfaces studied in surface science have low Miller indices, like (111), (110) and (100). These planes correspond to relatively close-packed surfaces that are atomically rather smooth. With fee materials, the (111) surface is the densest and smoothest, followed by the (100) surface the (110) surface is somewhat more open , in the sense that an additional atom with the same or smaller diameter can bond directly to an atom in the second substrate layer. For the hexagonal close-packed (licp) materials, the (0001) surface is very similar to the fee (111) surface the difference only occurs deeper into the surface, namely in the fashion of stacking of the hexagonal close-packed monolayers onto each other (ABABAB.. . versus ABCABC.. ., in the convenient layerstacking notation). The hep (1010) surface resembles the fee (110) surface to some extent, in that it also...

Tarazona A, Kreisig S, Koglin E and Schwuger M J 1997 Adsorption properties of two cationic surfactant classes on silver surfaces studied by means of SERS spectroscopy and ab initio calculations Prog. Colloid Polym. Sol. 103 181-92... 

Matsumoto H, Inukai J and Ito M 1994 Structures of copper and halides on Pt(111), Pt(IOO) and Au(111) electrode surfaces studied by in situ scanning tunneling microscopy J. Eiectroanai. Chem. 379 223-31... 

Barish E L, Vitkavage D J and Mayer T M 1985 Sputtering of chlorinated silicon surfaces studied by secondary ion mass spectrometry and ion scattering spectroscopy J. AppL Phys. 57 1336-42... 

Not intrinsically surface sensitive Surface areas >10 m /g required or desirable for surface studies... 

Because STM measures a quantum-mechanical tunneling current, the tip must be within a few A of a conducting surface. Therefore any surface oxide or other contaminant will complicate operation under ambient conditions. Nevertheless, a great deal of work has been done in air, liquid, or at low temperatures on inert surfaces. Studies of adsorbed molecules on these surfaces (for example, liquid crystals on highly oriented, pyrolytic graphite ) have shown that STM is capable of even atomic resolution on organic materials. 

Other fields of surface study were of course developing the study of catalysts for the chemical industry and the study of friction and lubrication of solid surfaces were two such fields. But in sheer terms of economic weight, solid-state electronics seems to have led the field. 

FIG. 3 The possible configurations of passing the surface 0(r) = 0 through the field 0(r) discretized on the lattice. Black circles represent 4>ijk < 0, whereas white circles > 0- The cubes represent the smallest pieces of the lattice of linear dimension h. For smooth surfaces studied here, cases of 3, 4, 5, and 6 vertices of the surface in a small cube are the only ones. The cases of 7, 8, 9, and 12 vertices in a single cube have not been encountered. 

The properties of the periodic surfaces studied in the previous sections do not depend on the discretization procedure in the hmit of small distance between the lattice points. Also, the symmetry of the lattice does not seem to influence the minimization, at least in the limit of large N and small h. In the computer simulations the quantities which vary on the scale larger than the lattice size should have a well-defined value for large N. However, in reality we work with a lattice of a finite size, usually small, and the lattice spacing is rather large. Therefore we find that typical simulations of the same model may give diffferent quantitative results although quahtatively one obtains the same results. Here we compare in detail two different discretization... 

Examine the results of these potential energy surface studies in these ways ... 

Matienzo, L. J. and Holub, K. J. Surface Studies of Corrosion-preventing Coatings for Aluminium Alloys , Applic. Surf. Sci., 9, 47-43 (1981)... 

Surface Studies with the Vacuum Microbalance Instrumentation and Low-Temperature Applications T. N. Rhodin, Jr. 

Surface Studies with the Vacuum Microbalance High-Temperature Reactions Earl A. Gulbransen The Heterogeneous Oxidation of Carbon Monoxide Morris Katz... 

The temperature behavior of low446,491,503 558 as well as high Miller index crystal faces of Au447,448 has been examined in 0.01 M perchloric acid solutions. For all gold surfaces studied, C, was found to decrease and Ea=Q moved to less negative values with increasing t 446-448 491503-558... 

J.L. Brand, A.A. Deckert, and S.M. George, Surface diffusion of hydrogen on sulfur-covered Ru(001) surfaces studied using laser-induced thermal desorption, Surf. Sci. 194, 457-474 (1988). 

T. Arakawa, A. Saito, and J. Shiokawa, Surface study of a Ag electrode on a solid electrolyte used as oxygen sensor, Applications of Surface Science 16, 365-372 (1983). 

G. Binning, H. Rohrer, C. Gerber, and E. Weibel, Surface Studies by Scanning Tunneling Microscopy, Physical Review Letters 49(1), 57-61 (1982). 

Weisenhom, A.L., Khorsandi, M., Kasas, S., Gotzos, V., and Butt, H.J., Deformation and height anomaly of soft surfaces studied with AFM, Nanotechnology, 4, 106-113, 1993. 

Zhong, Q., Innis, D., Kjoller, K., and Elings, V., Fractured polymer/silica fiber surface studied by tapping mode atomic force microscopy. Surf. Sci. Lett., 290, 688, 1993. 

De Marco R, Pejcic B, Prince K, van Riessen A (2003) A multi-technique surface study of the mercury(ll) chalcogenide ion-selective electrode in saline media. Analyst 128 742-749 Pejcic B, De Marco R (2004) Characterization of an AgBr-Ag2S-As2S3-Hgl2ion-selective electrode membrane a X-ray photoelectron and impedance spectroscopy approach. Appl Surf Sci 228 378-400... 

Zettlemoyer Center for Surface Studies and Department of Chemistry,... 

Surface studies are difficult in the case of many metal electrodes since their regions of ideal or perfect polarizability are very narrow that is, the potentials of anodic dissolution (or oxidation) of the metal and of cathodic hydrogen evolution are close... 

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