Gold Film

Fig. 4.60. Comparison of resonance Raman spectra with and without tip enhancement for 0.5 monolayers of brilliant cresyl blue on a smooth gold film. The tip increased the total Raman intensity by a factor of approximately 15, when positioned at a tunneling distance of 1 nm. Several other bands were made visible as a result of the tip enhancement [4.306].

X-ray diffraction confirms linear coordination in Au(PPh3)(C=CC6F5) and Au(H2NCHMe2)(C=CPh) with the short Au-C bonds (1.935-1.99 A) expected for bonds to sp hybridized carbon. Decomposition of these compounds in the vapour above 150°C is a potential route to very pure gold films [162],... 

AuMe2(acac) is being studied as a vehicle for laser CVD of gold films it has the expected square planar structure in the gas phase (Au—C 2.054 A Au-O 2.085 A) [168],... 

RAFT polymerization lends itself to the synthesis of polymers with thiol end groups. Several groups have utilized the property of thiols and dilhioesLers to bind heavy metals such as gold or cadmium in preparing brushes based on gold film or nanoparticles1 8 761 763 and cadmium selenide nanoparticles.763 76 1... 

Water Jacket Cooling Water Reflective Gold Film... 

The compound CsAu is ionic, Cs Au RbAu was also thought to be ionic owing to xs Rb in the lattice but is now thought of as being a semiconductor. The preparation of CsAu is from a gold film with Cs vapor. The gold film is first... 

The sensor ch consists of a glass de on to which a SO-nm thick gold film has been deposited. The gold film is then covered with a linker-layer to which a matrix of carboxylated dextran is attached. The dextran, which extends typically 100 nm out fi om the sur6ce, provides a hydrophilic, activatable and flexible polymer to which biomolecules can be coupled throu amine, sulphydryl, carboxyl and other groups. 

The hydrogen molecule does not chemisorb onto clean sintered gold surfaces at or above 78 K [147] but on unsintered films, a small amount of H2 is chemisorbed if gold surface atoms of low coordination number are present [148]. Stobinski [149] found that H2 can also chemisorb on thin sintered Au films if the surface is covered at low temperatures with a small amount of gold equivalent to 1-3 Au monolayers prior to H2 exposure. This suggests a fundamental role of surface Au atoms of low coordination number in the chemisorption process. Deuterium molecules also chemisorb in a similar fashion on gold films at 78 K and isotope effects were... 

Maaroof, A.I., Cortie, M.B. and Smith, G.B. (2005) Optical properties of mesoporous gold films. Journal of Optics A Pure and Applied Optics, 7, 303-309. 

Stobinski, L. (1996) Molecular and atomic deuterium chemisorption on thin gold films at 78 K an isotope effect. Applied Surface Science, 103, 503-508. 

Saliba, R., Mingotaud, C., Argoul, F. and Ravaine, S. (2001) Electroless deposition of gold films under organized monolayers. 

Figure 9 [171] shows the Au 4f emission of the nanoparticles at different steps of the sputtering. The as-cleaned spectrum (curve (a)) is equivalent to the published data of bulk gold. The Au/Si ratio was around 3.3, showing that the gold film was discontinuous. With further ion bombardment, the position of the 4f emission shifted to... 

The UPS indicated structure change is associated with size reduction as the discontinuous gold film is transformed into rod-shape and spherical particles with size of 5-10 nm. Accordingly, with size reduction the activity displayed in CO oxidation is also altered the rate increased from 6.7 X 10 to 2 X 10 molmin cm . Consequently, not only the gold-reducible oxide interaction is responsible for the increased activity, but also size reduction. Indeed, small clusters themselves are able to activate the reaction components shown by theoretical calculations performed for 10-15-atom clusters, which can activate easily oxygen [177,200], but in real catalyst, even at the smallest active ensemble, it consists of a few hundreds atoms. 

Figure 2 shows a representative XANES spectrum from a bulk gold sample (a 1 pm gold film) and a representative spectrum of gold reacted with oat biomass. 

Figure 2. Representative XANES of gold nanoparticles from an oat sample reacted with tetrachloroaurate for 24 h and a bulk gold sample recorded from a 1 pm gold film.

Pronkin S, Wandlowski T. 2004. ATR-SEIRAS—An approach to probe the reactivity of Pd-modified quasi-single crystal gold film electrodes. Surf Sci 573 109-127. 

Hutchison JE, Postlethweite TA, Murray RW. 1993. Molecular films of thiol-derivatized tetra-phenylporphyrins on gold Film formation and electrocatal)4ic dioxygen reduction. Langmuir 9 3277. 

Hoffman and Kordesch74,75 have presented a series of studies on the passive films on iron with particular attention to cell design. They have employed a so-called bag cell that allows for the in situ passivation and/or cathodic protection of the iron films. These were deposited onto gold films deposited on Melinex. 

Fig. 4. Sliding cathode phototube (41) showing evaporation sources (1, 2) for depositing the alloy film on the photocathode (3), shielded partly as required by the glass screen (4). A quartz window (5) faces the cathode and connection is made to a gold film anode evaporated from (6).

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