Gold features

We compare these monolayers with SAMs on gold. Features of the alkanethiol monolayers on gold which make them particularly attractive include their relatively uncomplicated preparation, their thermodynamic and chemical stability and mechanical strength. The stability transpires through the formation of a chemical Au—S bond which gives rise to two-dimensional lattice structure in which the head groups form an overlayer with a lattice constant of... 

Another attractive feature of pCP is its ability to pattern features on curved surfaces [45,46]. Jackman and coworkers demonstrated the versatility of pCP by patterning gold features on a cylindrical surface by pCP and selective etching [45]. 

After application of a single potential step/scan towards negative potentials, the ordered 2,2 -BP adlayer dissolves, and the entire substrate surface appears very mobile. Fractal, monatomic high gold features grow at step edges (Fig. 38c), their surface... 

A feature of L spectra of atoms with Z < 40 is the absence of the P2 transition, which is intense in atoms, such as gold, with higher atomic numbers. 

The kinetics of spinodal decomposition is complicated by the fact that the new phases which are formed must have different molar volumes from one another, and so tire interfacial energy plays a role in the rate of decomposition. Anotlrer important consideration is that the transformation must involve the appearance of concenuation gradients in the alloy, and drerefore the analysis above is incorrect if it is assumed that phase separation occurs to yield equilibrium phases of constant composition. An example of a binary alloy which shows this feature is the gold-nickel system, which begins to decompose below 810°C. 

A. Kumar, G. M. Whitesides. Features of gold having micrometer to centimeter dimensions can be formed through a combination with an elastomeric stamp and an alkanethiol ink followed by chemical etching. AppI Phys Lett (55 2002-2004, 1993. 

All four monohalides of gold have been prepared but the fluoride only by mass spectrometric methods. AuCl and AuBr are formed by heating the trihalides to no more than 150°C and Aul by heating the metal and iodine. At higher temperatures they dissociate into the elements. Aul is a chain polymer which features linear 2-coordinate Au with Au-I 262 pm and the angle Au-I-Au 72°. 

Features of the method Most metals can be deposited by this technique, usually on to steel or copper alloys as substrates. The most commonly deposited metals are nickel, chromium, tin, copper, zinc, cadmium, gold and silver. 

Surface features can also be revealed by etching, which permits identification of points of intersection of line dislocations with the surface, and this is valuable in determining the role of these imperfections in chemical processes [45,214] and, in particular, nucleus formation. Smaller topographical details can be rendered visible by the evaporation of a thin (<0.5 nm) film of gold onto the surface [215,216]. Heights and depths of surface features can be determined by interferometry [203—205]. Microcinematography has also been used [217] to record the progress of solid phase reactions. 

The greater dependence of rate coefficient upon acidity for detritiation compared to dedeuteration is apparent for benzene as it was for toluene and is more marked, but in view of the errors in the benzene work (which appear to arise only from measuring the acid concentration but could possibly arise from some feature of the kinetic method) and element of doubt must remain here. Nevertheless, this phenomenon (which is understandable on the basis that when the reactions are infinitely fast they will then both take place at the same rate, and the more reactive the compound and the stronger the acid, the more closely this situation is approached) seems to be general, for Gold et a/.460 found that the log rate coefficient... 

The microarray electrodes used for solid state electrochemistry are a slight variation of the transistor decribed in Sect. 5.2.2 The most appealing feature is the location of all the necessary electrodes on a single microchip, the reference electrode being provided by the application of a droplet of silver epoxy to one of the gold micro electrodes (Fig. 7). 

The turnover frequency (TOP) based on surface-exposed atoms significantly increases with a decrease in the diameter of the gold particle from 5 nm [66]. This feature is unique to gold, because other noble metals usually show TOFs that decrease or remain the same with a decrease in the diameter [7]. The decrease in particle size gives rise to an increase in corner or edge and perimeter of NPs and change in electronic structure however, the origin of size effects on catalytic activity for CO oxidation is not clear. 

Although bulk gold is poorly active as a catalyst, gold NPs attached to a variety of support materials exhibit unique catalytic properties in oxidation. The general features can be summarized as follows. 

Gold (111). The main feature of the gold (111) surface is that the... 

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