Silver thin films

Figure 5. Morphology and particle size distribution of an island silver thin film deposited on native oxide covered silicon (a) before ion bombardment and after (b) 0.5 keV Ar sputtering with 1.1 X 10, (c) 2.5 X 10, and (d) 3.9 x 10 ion/cm dose. Sputtering speed for silver was around 3-4ML/min. Total elapsed sputtering time is indicated on each size distribution graphs. (Reprinted from Ref [123], 2003, with permission from Springer.)...

Delgado JM, Orts JM, Rodes A. 2005. ATR-SEIRAS study of the adsorption of acetate anions at chemically deposited silver thin film electrodes. Langmuir 21 8809-8816. 

These studies were carried out on industrially manufactured piezoquartz resonators with an AT-cut featuring silver thin-film electrodes. Oscillations with a frequency of 10 MHz (resonant frequency) were generated by generator of the TKG-3 type. The sensor of silver atoms (films of zinc oxide) were positioned in the same vial with resonator, the sensor was positioned parallel to the resonator plane the distance between them was about 5 mm. Prior to the experiment the vial containing resonator and sensor was heated up to 473 K and kept at above... 

In 1988, Tanaka et al. first reported the use of ultrafine metal powder in protein analysis. Since then, many inorganic materials, including graphite particles, fine metal or metal oxide powder, silver thin-film substrates or particles,and silica gel, have been used in the MALDI-TOF analysis of low-mass molecules. 

Thin sheets of mica or polymer films, which are coated with silver on the back side, are adhered to two cylindrical quartz lenses using an adhesive. It may be noted that it is necessary to use an adhesive that deforms elastically. One of the lenses, with a polymer film adhered on it, is mounted on a weak cantilever spring, and the other is mounted on a rigid support. The axes of these lenses are aligned perpendicular to each other, and the geometry of two orthogonally cixrssed cylinders corresponds to a sphere on a flat surface. The back-silvered thin films form an optical interferometer which makes it possible... 

Thin films were first used for decorative purposes. In the seventh century, artists learned how to paint a pattern on a ceramic object with a silver salt solution and then heat the painted object to decompose the salt, leaving a thin film of metallic silver. Thin films are used today for decorative or protective purposes to form conductors, resistors, and other types of films in microelectronic circuits to form photovoltaic devices for conversion of solar energy to electricity and for many other applications (Figure 12.31 ). A thin film might be made of any kind of material, including metals, metal oxides, or organic substances. 

Silver thin films were modified using a novel plasma chloriding modification process for the development of thin silver film/silver chloride reference electrodes [39]. The influence of the formation of the silver chloride complexes (AgClj and others) on the potential of the sUver/silver chloride electrode was analyzed [40] at higher temperatures. At temperatures exceeding 150 °C the solubility products, the concentration of silver complexes and the concentration of free chloride ions are significantly different from those existing at 25 °C. 

In another work [81] a silver thin-film pattern was covered with a polyimide protection layer with a 50 pm wide slit at the center of the pattern and the Ag AgCl layer was grown from there into the silver layer. A liquid junction was formed with a photocurable hydrophihc polymer. A silicone rubber passivation covered the entire area except for the pad and the end of the junction. The complete miniature liquid-junction reference electrode could maintain a stable level within 1 mV for time longer than 100 h with the aid of poly(vinyl pyrrolidone) matrix in the electrolyte layer. 

H.C. Kim, T.L. Alford, D.R. Allee, Thickness dependenee on the thermal stability of silver thin films. Appl. Phys. Lett. 81(22), 4287-4289 (2002)... 

Esfandiar, A., Savaloni, H., Placido, E, 2013. On the fabrication and characterization of graded slanted chiral nano sculptured silver thin films. Phys. E. 50, 88—96. 

The first work published in this area was that of Bigelow mentioned above [116], In 1957, monolayers of long-chain fatty acids were fonned on thin films of silver, copper, iron and cadmium deposited on glass microscope slides [43],... 

Birss V I and Smith C K 1987 The anodic behaviour of silver in chloride solutions-l. The formation and reduction of thin silver chloride films Electrochim. Acta 32 259-68... 

A typical Ag/AgCl electrode is shown in figure 11.9 and consists of a silver wire, the end of which is coated with a thin film of AgCl. The wire is immersed in a solution that contains the desired concentration of KCl and that is saturated with AgCl. A porous plug serves as the salt bridge. The shorthand notation for the cell is... 

The (Ti02) films are also appHed to glass or vitreous enamel for decorative purposes. Thin films enhance brilliance thicker films impart a silver-gray luster. Milk glass can be produced by mixing the titanate with a low melting enamel, which skaters when the coatkig is baked (424). 

Electrical and Electronic Applications. Silver neodecanoate [62804-19-7] has been used in the preparation of a capacitor-end termination composition (110), lead and stannous neodecanoate have been used in circuit-board fabrication (111), and stannous neodecanoate has been used to form patterned semiconductive tin oxide films (112). The silver salt has also been used in the preparation of ceramic superconductors (113). Neodecanoate salts of barium, copper, yttrium, and europium have been used to prepare superconducting films and patterned thin-fHm superconductors. To prepare these materials, the metal salts are deposited on a substrate, then decomposed by heat to give the thin film (114—116) or by a focused beam (electron, ion, or laser) to give the patterned thin film (117,118). The resulting films exhibit superconductivity above Hquid nitrogen temperatures. 

Thin films of photochromic glass containing silver haUde have been produced by simultaneous vacuum deposition of siUcon monoxide, lead siUcate, aluminum chloride, copper (I) chloride, and silver haUdes (9). Again, heat treatment (120°C for several hours) after vacuum deposition results in the formation of photochromic silver haUde crystaUites. Photochemical darkening and thermal fade rates are much slower than those of the standard dispersed systems. 

Thin films of photochromic silver complex oxides were prepared by anodic oxidation of silver metal films (15). Complex oxides, such as Ag2V04, Ag SiO, and Ag2P04, darkened by exposure to visible light, but required heating to 150—250°C for thermal bleaching. 

Electroless reactions must be autocatalytic. Some metals are autocatalytic, such as iron, in electroless nickel. The initial deposition site on other surfaces serves as a catalyst, usually palladium on noncatalytic metals or a palladium—tin mixture on dielectrics, which is a good hydrogenation catalyst (20,21). The catalyst is quickly covered by a monolayer of electroless metal film which as a fresh, continuously renewed clean metal surface continues to function as a dehydrogenation catalyst. Silver is a borderline material, being so weakly catalytic that only very thin films form unless the surface is repeatedly cataly2ed newly developed baths are truly autocatalytic (22). In contrast, electroless copper is relatively easy to maintain in an active state commercial film thicknesses vary from <0.25 to 35 p.m or more. 

Thin films of metal can be prepared by vacuum evaporation and condensation on a suitable support. For exatrrple, tlrin films of silver can be formed on a... 

The outstanding characteristics of the noble metals are their exceptional resistance to corrosive attack by a wide range of liquid and gaseous substances, and their stability at high temperatures under conditions where base metals would be rapidly oxidised. This resistance to chemical and oxidative attack arises principally from the Inherently high thermodynamic stability of the noble metals, but in aqueous media under oxidising or anodic conditions a very thin film of adsorbed oxygen or oxide may be formed which can contribute to their corrosion resistance. An exception to this rule, however, is the passivation of silver and silver alloys in hydrochloric or hydrobromic acids by the formation of relatively thick halide films. 

Figure 10-12. Lcfi hand side Slruclure of a PPV microcavily. A thin film of ihe conjugated polymer is deposited on top of a highly reflective distributed Bragg refieclor (DBR). The second mirror is then fabricated by evaporation of a silver layer. Right hand side Emission spectra of the microcavily at excitation cnetgics or 0.0S pJ (dashed line) and l. l pJ (solid line), respectively. Laser pulses ol duration 200-300 ps and a wavelength of 355 nm were used for optical excitation (according to Ref. [39]).

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